Depending on what you mean by "fix the geometry", you should have all the tools you need in the part module. You can create/delete/edit features that you have created yourself. E.g. solid/shell/wire features like lofts, revolves etc can be easily fixed.

You can also create new features (solid/shell/wire) on top of existing geometry, including geometry that you have imported.

The repair geometry toolset (where you can delete faces, ctreate new faces, collapse slivers, merge edges, and so on...) is a very useful additional set of tools, hence the name "toolset"??! ;) You should experiement and read up on how you might use these tools in conjunction with the paramteric feature-based geometry creation tools.

If you need more help you'll have to be more specific...

As brep says you can go back to the part module at any time to change/modify the part. One of the problems to watch out for is that some features may be lost ie. partitions or even property assignments, so you may have to repeat those. I don't see how geometry repair will help unless you found a problem in meshing the part. Some times spurious points can be inserted into the part which will upset the meshing, or even make it impossible. Removing redundant entities in the part module with the geometry repair tool cures that. On occassions importing a part from a CAD drawing will also cause problems later as lines won't meet or slivers will exist. Repairing the geometry will cure that or alternatively just ask whoever to correct it before importing into Abaqus.

corus

The big diminishing message that makes modifying a part or adding a feature to it cumbersome is " Section must not Self-Intersect". I do not know if there are some strategies that can be recommended to make life easier in this regard (playing with the part flexiblly without loosing features; e.g. using sketch-Alone)

Try trimming the entities in the sketch (there are a number of trimming tools available). In this respect, CAE is no different than other 3d CAD modelers