E36 Wheels and Suspension questions

Hi All,
I have a '96 328i, all stock, with about 96,000 miles. I bought the car
in 2002 with 54,000 miles on it. I live in the New York city area.
Some questions on a couple of topics:
1- Would there be any suspension components/ bushings due for replacement
srtictly based on this mileage? If so, recommendations?
2- I'd like to switch from the original 15" wheel/tire setup to 16"or 17"
when I take off my snow tires next spring. I see a lot of aftermarket
wheels, at tirerack for example, that are said to fit the car, but have a
different offset than the stock BMW wheels. How important is it to maintain
the exact offset? Is there an allowable difference of a few mm? What about
the use of spacers? They don't seem like a suitable alternative seeing how
the stock wheel sits over the center hub.
TIA to all!