I’m trying to speed up my computer a little bit, and apart from these useful tips I’m trying to remove all Visual Studio extensions and add-ins that I don’t use anymore.
I noticed I have both ASP .NET MVC 2 and 3 installed side-by-side, and I don’t use version 2 at all.

Can I safely delete the old version, or does MVC 3 depend on MVC 2?
I don’t want to mess up my working environment.
Yes.
MVC 2 and MVC 3 are completely independent.