1) Since the "best" universities ranking is just a perception, everyone is looking at the same lists. So the online rankings are self fulfilling.
2) Almost everyone works for some entity, like a municipality or design firm. Very few free lancers out there. And if they are, they're very specialized.
3) Probably not, but I'm not sure what the difference is between a first rate vs. second rate school. The first rate school might be cheaper.
4) Most people work more than 8 hours, but there are very good engineers who "punch the clock." Depends on the project.
5) Most schools will shake out students who can't do calculus and higher level math courses. So yes, good enough to get through school. There's Engineering Technology Degrees for more hands on work without math. Lot's of day to day busy work, interspersed with real thinking designs.
6) Ask local Civil engineers.
8) No to PhD, unless you're very interested in higher level courses. Yes to Masters.

Go on line and look up ASCE. The you will get lots of information. It's not the highest paying engineer jobs, but sure has a lot of different fields to work in as a CE.

I founa Masters helped me very much to get a jump on the graduates.

1) Not overly useful in Canada but since you are in the United States it might in that the quality of engineering programs between Universities is more variable
2) Almost everyone I know works for a consulting firm, construction company, municipality, mining firm, etc. The only people I'm aware of that practice as individual consultants are legendary-tier engineers in specialist fields who don't want to quit working and never built their own firm
3) I doubt it
4) in my career I have worked everything from 21 days on, 13 hour days with 4 days off in a remote camp to 7.5 hr days working from home 2-3 days a week with 6 weeks vacation a year. Generally speaking expect crunch times / longer hours before project deadlines
5) You do need to be good at math but you can squeeze by without being amazing at it. In Canadian programs after first year alot of the base math is repeated between engineering courses (eg, solving systems of linear equations, hookes law)
6) find someone who works at a consulting firm
7) If you want to practice in a specialist field like geotechnical or structural a masters could be useful, PHD if you're really passionate about it and want a huge depth of knowledge.

(1) I agree with JedClampett. It's also important to note that the rankings are at least as much subjective as they are objective, and I strongly suspect the rankings don't reflect year-to-year changes in the programs. For example, I graduated in 1980 with a B.S. in civil engineering from California State University, Fresno. I thought at the time that this was a good, mid-tier program and my interactions over 40+ years with engineers from lots of different universities bears this out. I got a quality education--not as rigorous as the best schools, but better than many other schools. Unfortunately, within a few years after I graduated the program had hit hard times...and it's NOT because I left . Many of the really good professors werre retiring, including the chair of the program, and the program had lost of a lot of the foreign students that kept our numbers and class offerings up. It took a while for the program to rebound, but I never really noticed a change in the rankings during this time, and I did check them every couple years just for fun. More important to me is ABET accreditation and the number of students in the program. Small programs have limited class offerings and may only offer some classes once a year and these can be cancelled if not enough students choose to take it. Large programs tend to be more well rounded and cover more subdisciplines within civil engineering. On the other hand, a really large program might intimidate some incoming students.

(2) I have mostly worked in a company setting, but I also worked for myself (and by myself) for a few years. In one small company, I was part owner. In another, I gained enough seniority to become one of about 100 stockholders out of about 600 employees. I currently work for a large multi-national, multi-discipline company and I plan to be here until I retire. Most of the one-man shops I know are structural engineers who work mostly for architects as a subconsultant. I also know a couple one-man shops who design subdivisions for small developers. The type of work I do mostly requires a team of engineers, drafters, and sometimes specialists, so freelancing really doesn't work here. Also keep in mind that civil engineers are heavily represented in government (e.g. city and county public works departments, regulatory agencies, etc.) and are also found in utility companies, software companies, etc.

(3) Unless the better university offers a real tangible benefit in terms of quality of education and starting salary, I don't think it's worth it, at least if you are thinking about a private university and have no scholarship money to back you up. Fortunately, civil engineering offers a better than average chance of paying back the loan. In California, the taxpayers heavily subsidize the University of California, California State University, and Community College systems, so the relative cost is pretty low compared to a private university. My three kids all started at a community college and this worked for their majors. Even though many community colleges offer lower division engineering classes, I usually recommend engineering majors start at the university level. Engineering classes start in the first semester and there is a lot of benefit to being in the program from the beginning. If money is an issue, I think a good California State University is the optimum choice, especially if there is one close enough to home to live at home for at least a year or two. Then, if you have to take out student loans, they won't be a back-breaker.

(4a) The standard workday is 8 hours and the standard workweek is 40 hours, but the real workday and workweek in consulting vary according to project requirements and deadlines. I don't write the following to scare you, just to alert you to the fact that some career paths involve more work than others. My longest workday was 23 hours (it would have been shorter, but a computer crash cost me several hours). I have a full man-year of 90-hour workweeks under my belt (a 4-month stretch, a 7-month stretch, and four individual weeks), and I have often worked 60, 70, or 80 hours per week. In most cases, this was due to inadequate staffing (for years, it seemed that every time we would hire people to ramp up for a big project, the same number would quit at about the same time). However, the 4-month stretch of 90-hour weeks was due to a client changing project requirements on a very large project up to the last minute but not extending the deadline. Ten of us were on this train ride. Over the course of my career, I have averaged more than 50 hours per week. On the other hand, I know plenty of consulting civil engineers whose circumstances have allowed them to average around 45 hours per week. In my current role, I average about 42 hours per week, which is MUCH better. Government engineers tend to average much closer to the 8/40 standard.

(4b) Project durations vary widely. My shortest project ever required 3.0 hours. A client had asked me to update a 5-year-old calculation I had done for him using new assumptions. My longest projects have lasted more than 3 years from the beginning of planning through the end of construction. Most projects I have personally managed lasted anywhere from about three months to one year from start to finish.

(5) You need better math skills in college than you need for practicing civil engineering. The four semesters of calculus and differential equations in a typical engineering program serve two purposes: [1] provide the mathematical foundation for subsequent engineering classes and [2] act as a gate-keeper for who should and should not be in the engineering program. Most of my math needs in civil engineering are covered by algebra and trigonometry. I have used calculus a handful of times (like less than half a dozen) and I do some simple statistics. I have solved one small matrix on a calculator. So, not too difficult. For the slightly more difficult stuff, I use Mathcad.

(6) ASCE and local engineers are the best source of information. ASCE will give you the overview and local engineers can give you the details.

(7) Most of civil engineering does not require a masters, but it can be beneficial. I don't have a masters because at the time I could have fit it in to my life, the nearest university that offered a masters in civil engineering was a two-hour drive away. On the other hand, I have more than the equivalent of a masters through self-study and work experience. A PhD is appropriate for narrow specialist, but less useful for a "regular" consultant. My company has lots of PhDs, but they are all specialists.

I hope this helps.

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"Is it the only lesson of history that mankind is unteachable?"
--Winston S. Churchill

1 & 3) The US civil engineering degree is basically a pipeline to taking the fundamentals of engineering exam and then the PE. The content of your undergraduate degree won't vary much between universities. If I could do it again, I would have lived at home with parents, gone to a local community college for cheap, transferrable, math and science credits, then went to a reasonably-priced in-state school to graduate with a master's degree as fast as possible. DO NOT EVER get a civil engineering PHD, unless your current employer will subsidize it. It means next to nothing in the industry, except at the high levels where it's just a political credential. If you can graduate with a master's degree and have basic coding and programming skills, you will be an asset.

TLDR: Learn local, get master's degree w/ minimal debt.

Quote (DrZoidberWoop,)

gone to a local community college for cheap, transferrable, math and science credits

Maybe things have changed in the considerable time since I went to college or maybe it was regional, but as I distinctly remember, the community college (called junior college in my day) transfers went through hell. The classes, even with the same name were not considered equivalent. It seemed that the University, as an entity, thought their classes were better than the community college ones, and wasn't going to accept them. So instead of having 2 years in, they had more like 1 1/4 or 1 1.2.
The lifestyle change (being away from their home/parents/support system) was difficult, but now you weren't with freshmen, all experiencing the same issues, but with upper classmen, who had either adjusted or weren't there anymore.
I know California had a better pipeline from CC to universities than the Midwest and maybe that's all evened out.

I had just the opposite experience. I tried to transfer from one university to another and some of those credits didn't transfer. however the credits from the community college did. I ended up re-taking calculus and physics. this was un-planned, so really couldn't have avoided it.

any time you plan to transfer, make sure you check into things first and don't waste your time.