I'm not sure if that pressure is low or not since I'm not familiar with the press/temp characteristics of the alternative refrigerant. If it were R12, I would definitely say that it is low.

Yes you can indeed defeat the sensor using an ice cube relay in place of the klima relay if you are comfortable fabricating such electrical items. It is very possible that the compressor is just worn out allowing thrust movement of the guts which is tripping the trigger. There's no way to know for sure, short of replacing the compressor.

The klima relay is behind the battery. Remove the plastic cover behind the battery and it will be at the right side of the row of modules. You really need an FSM, but you might can search the forum and find the wiring diagrams you need.