Is there any way to let Facebook run only when I want? Is there any way to let the Facebook app run only when I want to use it and really close it when i don't need it?

I've already disabled it with autostarts, moved to sd, yet it is still running 24/7.

I don't want to appear on the Facebook chat, also don't want to waste 30mb of ram, and of course there are no FB widgets on the home screen
You could always install Titanium Backup (a GREAT app to have) or App Manager (was just released today by JRummy) and "Freeze"/"Unfreeze" the app when you want it to run or not run. This is a very quick/simple/painless operation and there's absolutely no chance for it to run (taking up resources or draining battery) while it's "Frozen" - it just takes up a bit of storage space is all.