I am currently driving my 93 rx7 what i believe is called the 'the air leak' fully closed(righty tighty) because it seems the screw loosens itself over time if i don't force it closed, causing the engine to go lean. My question is how open should the air leak be(in rotations) and is there any suggestions on how to prevent it from opening further after being set?

 

you can try a bit of threadlocker (by Permatex).
You don't need to get the Ultrastrong stuff..just the stuff that will prevent the screw from backing out. (they do make stuff to prevent the Flywheel nut from coming off..so do NOT use that..lol!)

 

Clockwise will close and lower your idle. Don't think there is a specified 'setting' for it...every car is a bit different. But I'd try to stay as near to closed (lower idle) as possible.