There isn't really anything worth upgrading on that system. The money would be better spent on a rebuild with a new CPU, motherboard, RAM and video card.

Were you expecting an official response within 10 minutes of a post made at 1am? I would err on the side of caution and not use the FXAA injector until someone from Bioware makes a post about it. Do your video card's transparency AA options not work in SWTOR?

This sounds like a question for a GM. Have you opened a ticket ingame?

A bit of Google-fu shows that the error probably means that you haven't installed the Visual C++ 2008 redistributable, which is a dependency for SW:TOR. You can use Dependency Walker to scan the SW:TOR executable to verify this. http://www.dependencywalker.com/ If Dependency Walker confirms that a missing/corrupt VC++ 2008 is triggering the error, you can download it from the Microsoft website. https://www.microsoft.com/download/en/details.aspx?displaylang=en&id=29