My 83 300D has been running what I think is warm, a bit under the 100C mark on the guage. Today I changed the thermo and put in new MB coolant and a new radiator cap. Still runs warmish, just under 100C. If I turn up the heat all the way the temp guage will drop quickly to maybe 3 needles width above 80C. No leaks anywhere and no wierd smells from the heater or under the hood.
Unscientificly feeling across the top of the radiator and it's hot everywhere. The drained coolant was very clean, no signs of scaling and in fact looked like it had probably been changed not too long ago.

Questions:
1. The fan clutch, Car is hot, I try to spin the fan and it'll go maybe a half a turn or so after I let go. Definitely some resistence there. Is this OK?
2. Water pump. No dripping or anything. Can it just plain wear out or would it leak if bad?
3. Pressure. There definitely pressure in the system, not a lot though. I was able to remove the rad cap hot with just a little hiss. Is this right or should there be a lot of pressure.
4. Am I being too anal, is below 100C ok for the old beast.
5. Could poorly set valves cause the car to run hot. I haven't yet set them and although the car runs good I do not know the status of the valve adjustment.
Thanks for any advice.