hi, welcome to AF. don't know the answers to all your questions, but i'll try to knock out a few.
3.) they have belts that should be changed on the manufacurer's schedule (somewhere around 60-70k for the first time). haven't heard anything bad about the belts except when you don't change them in time and let them break then it could cause serious damage. only the 4.2s have timing chain.
5.) check out the turbos first and formost b/c it's the most expencive to repair. during the test drive if the turbos make a high-pitched drilling sound rather than a soft whinning sound thats no good. then after a good strong test drive, go to the front of the car and see if you can see any type of steam emmit from them, or you can even smell them if they are going bad. only other thing to watch out for is the control arms. if you hear a squeek when you push down on the 4 corners then thats a clue.
8.) you should be able to ask any technologicaly up to date machanic your cars maintanance schedule in relation to it's milage. or you may even be able to pull it up on line somewhere.
anyway, get it in shape and post some pics. we would luv to see them!!!!
