Hi Arthur, moved to Taree yet?
Well it does look like the lock-up clutch is jamming. This will be because some of the lining has flacked off to jam it. Some of these bits may have traveled down to the cooler and have lodged there also. So give it a clean when you do the transmission change. Swapping the speed sensor is not a big job to do before you fit it, the holes are already drilled and tapped.
Can't help with. the AC, except that I have scans of the system and the code procedure in my old locker here:
http://www.subaru-svx.net/photos/user.php?oab_au|35851
It may give you a clue to the problem.
Harvey.