When you're talking about possibly having to remove 8 lugs in the back-wild, I'd definitly go with steelies- I've seen enough aluminum rims seized with lug bolts to never want to go there. There was one on a Grand Cherokee that I tore down which I wound up leaving on the axle I pulled- the guy later took a hole saw just to get the tire off the axle so the tire and axle could be salvaged.
Less backspacing means your rims stick out more, the main result being at full lock (turned all the way) you won't hit control arms/springs and when your tire goes up into the wheel well it is more likely to hit the fender. Turning radius, stability, and looks are all affected, but none of that matters if you're tearing up your tires with too much or too little.
One possible reason to go with more backspacing is if you get wider tires enough to start rubbing on the springs or not being able to lock fully.
Offset is based on the rim width, whereas backspacing is not. Zero offset means the mounting surface is in the center of the rim, which is different for a 7" wide rim than a 10" wide rim in terms of backspaceing (3.5" and 5") the result is the same as far as centering goes.
Clear as mud eh?
good to be back