Don't be afraid to use the search function buddy.
But I'll be nice and answer these.
If you got 3" lift spindles, you'd want to put a bigger block in the rear, OR install Chevy Drop shackles (which lift the Ranger 2-ish inches), OR do an AAL (ADD-A-LEAF).
You could fit 32's just fine.
It will slow it down, but you'll only notice if you go from like a 235 sized tire up to a 32 or something like that. Not THAT much of a difference. Look around some more, research up, you'll find everything you need.
2012 Jeep Wrangler Unlimited Sport