A red screen? Does it look at all like the BSOD?

Yeah, it will first see if it has the drivers for your kernel...then it will try to find them online...then it will build them for you. So you have to go through two things before you get to the compile option (which is the third and last).

I dunno about rivafb. But the README.txt does mention that:
Q: My system hangs when vt-switching if I have rivafb enabled.

A: Using both rivafb and the NVIDIA kernel module at the same time is
currently broken. In general, using two independent software drivers
to drive the same piece of hardware is a bad idea.
So it sounds like it there's no harm in installing. I'm sure rivafb can be disabled if it causes trouble. I spose it's also possible that one of the older driver sets might not have this issue.