Does it drive OK. Idealy you want the front back to where it started. Or check your manual. Some want it to come back 1/2 way, and you have done that. If the Steering is normal, no sway. You are OK. A 2" drop in the rear isn't all that bad, and if the front is good. You are good.
Remember. Get the front right, and the rear will take care of itself.
NO Air bags will do nothing to return lost weight to the front.
Terry & Shay
Coachman Apex 288BH.
2013 F150 XLT Off Road
5.0, 3.73
Lazy Campers