For the AC shutting off on certain settings, check out this thread. I had that same issue recently and this was the solution. Best part is that you don't have to buy any new parts.
http://www.mazdas247.com/forum/showthread.php?t=123678787
That's right where my 02 P5 is... well 147,000 anyways. My commute is an hour, but the last couple years I've been carpooling so I only have to drive every 3rd week. Anything to keep her alive ya know?