Static pressure is too low.... should be at least 80-85 psi or >, depending on ambient temperaure. Your refrigerant charge is too low. Are you seeing any bubbles in the R/D sight glass? Or just oil slicks?

As to the inability to charge... is your charging technique proper? What engine RPM are you charging at?

Compressor is likely worn, also. Is this the factory original compressor? At your current refrigerant charge level, you should see a greater dip into the negative on the suction side as the RPM increases above 1500.