Having gone through this already I may be able to shed a spark of light.
Disclaimer: I knew/know next to nothing about IDEAS. I came from "another CAD system" to NX, and was tasked with getting the transition going from IDEAS to NX. Also, our drawings reside in the same part as the 3D. If our drawings were separate files, Drawing Templates might have worked. At least from I could understand.
I didn't like title blocks created as symbols because I thought it was too easy to highlight the title block and move it slightly or delete it.
That said, our title blocks come in two pieces. For everything that won't ever change from drawing to drawing, like sheet outlines, standard notes, field titles like Date, Drawn By and the like, etc. there is a pattern. I liked patterns because they are hard to select. You have to go to absolute zero and usually wait for the selection box to pick it. So there's no deleting it or moving it by accident. For the stuff that will change, like the actual title and information specific to each drawing, there is a part. Each of these 'changeable texts' is a Table. This part is imported. After looking at patterns it became obvious it was going to have to be done this way because the tables couldn't be included in a pattern.
I suppose that you could import the entire title block, text tables and all, as a separate part, but then you'd still be able to move or delete stuff that shouldn't be.
So there's my two cents worth. There may very well be an easier way to do it for our specific case, but this was the easiest that I could come up with.
Mike