1-Should be a placard in the engine bay that indicates the charge.
2-What coolant? 134A, seems to be around 20s-30s low/200+ high, so you're off by a fair bit.
3-I think on those Type III climate control systems, the compressor is on full-time, and is not cycled on/off to modulate the temperature.
4-?

__________________
1983 Mercedes-Benz 240D
Automatic, A/C, Power Sunroof, Power Right Side Mirror
231K Miles FOR SALE MAKE OFFER