Does anyone have a script to prevent or auto suspend users that use a lot of apache / cpu in cPanel?

No, but you could maybe ask the folks from bluehost.com if you can have a copy of theirs.

I think to do this, you will need to modify the linux kernal, and then build your own script to interact with it. My understanding of the current kernel is that it does not provide this kind of reporting capability as-is. (I'm often wrong, however...)

No, but you could maybe ask the folks from bluehost.com if you can have a copy of theirs.

Bluehost doesn't auto suspend the account, they just discard the requests which are trying to take above the amount of cpu or memory, it is done for each process instead per account.