1 - the title this page is wrong.
You need to blacklist it under /etc/modprobe.d/.
You need to blacklist with:
- echo "blacklist nouveau" > /etc/modprobe.d/nouveau.conf
3 - Confused?
Let's emerge our kernel:
(chroot) # emerge debian-sources
Put a condition to make this compilation. Apparently it looks like it's to do this install now. And this is not the case. Besides this an instruction has to update @world before restarting. Would not this update this kernel?