A/C blows warm air

Although I am not technically an AC mechanic, that sounds to me as though the expansion valve is stuck open. You should also fix that leaking shrader valve.
You may need a J 46246 valve core tool.
Of course you will have to recover the Freon for both procedures. although R134a is supposed to not harm to ozone layer, I still do not think it is legal to just allow it to escape into the atmosphere.
Here are the instructions for replacing that expansion valve.
Recover the refrigerant. Refer to refrigerant recovery and recharging .
Remove the air cleaner assembly. Refer to air cleaner assembly replacement for the 2.2L (L61) engine or air cleaner assembly replacement for the 2.4L engine.
1. A/C evaporator and condenser hose nut.
2. Sealing washer.
Remove and discard sealing washers. Refer to sealing washer replacement .
3 Thermal expansion valve bolts (Qty: 2).
Tighten: (62 lb in)

4 Sealing washer.
Remove and discard sealing washers. Refer to sealing washer replacement .
5 Thermal expansion valve

Your system is nearly empty of refrigerant due to a leak, probably caused by the leaking shrader valve. The system requires a very specific amount of charge. Too much is a problem, too little is a problem and it will likely need some refrigerant oil added also. The only way this can be diagnosed accurately is to completely evacuate the system, repair the shrader and recharge the system with the exact specified weight of refrigerant charge.

Wrenchtech, when it was charged both the high and low sides were the very same PSI, would not that mean the expansion valve is stuck open?

No, it means the compressor is not engaged.

He said, "noticed A/C clutch spins".

He could simply be looking at the pulley but regardless of whether it is electrically engaged or not, it is not creating any suction or pressure so it is doing nothing. Also, depending on what the outside temperature is at the time, that ambient pressure should have been higher meaning it does not have sufficient charge to even reach ambient pressure. If in fact it was very cool outside at the time, that may be a normal ambient pressure but until the system is evacuated and recharged, nobody is going to know if it is charged correctly.

Since I need to evacuate the Freon to replace the shrader valve, why not replace the expansion valve, charge it up to the right Freon specs/oil and try the pressure test again hoping the compressor does its job?

Because the expansion valve is not your problem. The symptoms do not indicate anything wrong with the expansion valve. I live in South Florida and I specialize in AC repairs.