i really honestly can't remember anything that explicitly says visual studio that can't be removed, but i'm not going to suggest you start deleting files from program files.
Well, no doubt! The redist packages usually contain the dynamic libraries for most programs to run properly. Then you get into VM, and things really get complicated. It would be a suprise to see any external application that requires Visual Studio runtimes actually work without the libraries.
Then there are updates for versions of Visual Studio. Then there are OS-specific versions, etc etc....
What you could do is just uninstall VS and install the redist package and see if everything works.
If something doesn't work, it will usually point out what version and file you require for that specific application to work. Or you will blue screen. (Even with that it will point out which file is required.)
I would back up everything first. Then note what redists are installed, and just install the latest redist and try it. 9 times out of 10, everything will work flawlessly. It's not a sure-fire solution, but it might be one for some people.