Being a recent 944 owner myself I can take a stab answering a few of your questions
1) whats the normal oil pressure regarding RPM?
While stationary my pressure falls between 2-3 during driving stays between 4-5.
2) whats the normal temp?
Before I got my thermostat and water pump changed water temperature stayed in the lower half of the scale. Now after warming up it consistantly remains on 3/4th. It all depends on your thermostat.
3) does acquiring a chip worths it? If so which?
I just got the autothority chip for my '87, and YES, you can definately feel the difference
4) does acquiring a throttle cam worth it?
From what I heard yes, it is worth the $25. That's next on my list.
5) someone drives it in winter?
Why not? Some use their 944's as sole transportation. The body is galvanized, little chance of rust.
6) how the ... do you remove the top???
Someone beat me to this one
PS. Wanna sell me the 911???? :>