1. If you wire a manual switch to the compressor, the ECU and the IACV will not know to bump up your idle. Either your fuse or relay is bad, or you're tripping the dual pressure switch with your improper charge.

2. R134a, when charged correctly, is cold as shxt. In my car, my keys get condensation on them because the hand vents blow directly on them. Also, my S13 + R134a destroys my WRX AC, which was designed for R134a.

3. Pay the money to get it charged correctly. I'll just go out on a limb and assume that when you put your AC back together, you just dumped a bunch of freon in there. That is exactly the wrong way to do it because you're leaving air in the system. A professional will suck all of the air out first (evacuate the system). Lets add it up. Not very cold = improper charge. Dual pressure switch tripping = inproper charge. ding ding, we have a winner!