1) It depends entirely on the generation and the how well it's been mantained. Usually, taken care of, any Ranger will push 200k easy. But, they do go bad if you don't take care of them.
2) Google KBB or Kelly Blue Book. Generally if the vehicle has over 15,000 miles per year start lowering the price.
3)What year, engine? 4x4 or 4x2? Manual or Auto?
4) YES. On my 94 3.0L I went from 15 city to 12 when I got bigger tires, BUT I also did not re-gear the rear end.
S-Mart Corporate Security Division
Necronomicon Retrieval Specialist