su which support wheel and libcX

[Fathar W. Ulum]

Hello,

Q1: I know that "su" program on linux doesn't support wheel group like in
BSD but I don't want an ordinary user has access to root so where can i
find "su" program that support wheel group? or where can i find the source
code?

Q2: How do you identify which library is on your machine? libc5 or libc6?
and which one is compatible with glibc2.x or glibc1.x ?

TIA,
F