Honestly, the players that you kept from last year are your safest bests. However, if you felt like you could do better with a wide receiver, I would be tempted to take a chance on LeShoure instead of Wallace.
Ryan and Hilton (i go for mix of young players in keeper leagues and i think hilton will do better next season...not shabby fantasy wise this season).
not sure about #3. i'd let sproles go to FA but pick him up asap in the draft. he won't last long and one of my fav players since he's a 3-way threat. tough season 2012 which will turn around 2013. gl!