10 years and no problems except for intake gaskets and oil seals. It's not a daily driver though. With normal non boost driving, it is like any other fox body. When in it with boost, its just like anything that creates more power than stock, things get pushed closer to limits (tires, axles, trans, u-joints, torque boxes, etc)
Pretty much like no life said. Eventually the blowbye the car gets will push a few gaskets out here and there (not head gaskets). Thats the only extra maintinence. It all depends on how well you put it together mechanically and the tune.
If its built properly it shouldn't make any different boosted or otherwise. I daily a boosted vw with no issues. And if your worried about blowing seals get a breather to let out the extra pressure and you won't have any issues
Just make sure your pcv system is vented to atmosphere and not putting boost in your crankcase. Ive dd a 600 rwhp supercharged car before and never had an engine issue or had to replace a gasket, everything was vented properly tho. Two years or more I drove it, got 20mpg on premium too.