Congratulations on getting an extremely rare car!
To answer your questions:
1) Regular maintainence like fluid and filter changes, and normal 30k and 60k service should be enough for a Camry. Hell, my camry has 76k on it and the most expensive thing we've even done on it is a tune up (reminds me, i gotta change my timing belt soon).
2) I don't think there are any all trac specific issues on the 2nd gen. OEM parts are gonna cost you an arm and a leg, but just keep the 4wd system in top shape and you should be fine.
3) The guys here might be able to shed some insight on your 4wd system, though there aren't any specific camry all-trac forums that I know of:
http://www.alltrac.net/phpBB2/
Anyways, all-trac's are sweet cars, and if you are ever gonna be around the midwest and want to sell your car, let me know, and I would buy it this second.