Are you using X?? Because I think that S99rmnologin is necessary to make login in X. As you have gdm I guess so, so I recommend you not to "update-rc.d -f rmnologin remove".
I had some troubles when I decide to clean my rc2.d because I wiped out this service and then an error always was prompted when I tried my login.
If you don't want to share files through your LAN, you can remove nfs services.
If you don't want to RPC a server, you can clean portmap.
If you don't want ssh services (for secure remote access), you can clean ssh.
Probably, the easy way is knowing what services do you want to use.
But you can feel free to experiment with update-rc.d (you know, what happens if I wipe this...
Can't help with the other services.