Now, the "golden" question, as I have read in pretty much every post with people that have my same issue
You haven't read very carefully or, you are confusing the causes with the effect, a "generic crash" it's one thing, but your it's a G3D.DLL crash. G3D.DLL crash is not so common here, and everybody that had it, fixed by installing the latest FSUIPC so, it's exactly the opposite: your issue is unique, since nobody else so far has reported a G3D.DLL that wasn't fixable that way.
WHY is this coming up roght after installing GSX? There has to be a reason. There has to be a file that GSX modifies or replaces that causes this. Simply stating that this was going to happen sooner or later does not sound very reasonable.
The only file in FSX that GSX modifies, it's the default vehicles_airports.bgl, that is patched to remove the default two truck. No other file in FSX is modified, GSX only adds its own objects which are NOT called until you call a GSX service. Ig f the problem was the patch made to the default pushback truck, it should crash immediately after you go at an airport, and if the problem was one of the objects installed by GSX, the crash should happen as soon as you call a GSX service.
Since, from your description of the problem, the crash happens only after a while, it can't be any of these things, which are the only things that GSX adds to FSX. As I've said, the program doesn't do anything if you are not using it, and even if it's waiting for you to call it, it's doing this externally so, anything that happens in the GSX internal logic CANNOT crash FSX, plain and simple.
You might have noticed it only after GSX, but that was probably coincidental. The installer does a minor change to your FSX.CFG but it's usually not needed: it simply ensures you have the "Advanced Animations" flag set and sets it if it's not (99% of users already have it set), nothing else is changed.
On the other hand, I would like to FULLY delete your program. I would like my simulator back to its normal working condition, previous to GSX install. How can ALL traces of this software be deleted?
With its uninstaller, replying YES to "Do you want to remove the Addon Manager ?" and to "Do you want to remove the Couatl engine ?" This will remove everything related to GSX. None of our other products will work either, but this is a 100% clean uninstall.