If the idle was OK before the throttle body was replaced, and then high afterwards, why would you assume that it was set properly by the installer? I would take it back and have them set it correctly.
As far as the A/C, you're obviously leaking refrigerant somewhere. If UV dye has been installed in the system, you should be able to locate it with special glasses and lighting. If not, you'll need a "sniffer"
Recharging with that fast of a leak is going to be a constant battle keeping the refrigerant at optimal levels...
Heath