Is it bouncing long after the truck hits a bump. Like 50 or 100 feet down the road? Or is it a harsh ride? I am thinking you are calling a harsh ride bouncing? I would tend to doubt it is bouncing if you have brand new shocks. Even the wrong application shock will be better than worn out ones. The 5000s are overkill is all, a good set of stock application heavy duty shocks are fine for a driver mild trail rig.
(1) Its a truck, the best riding truck is a half ton, long bed, 2 wheel drive. Even they ride like a truck. A short bed 4x4 is going to be a harsh ride no mater what you do to it. The problem with taking springs out is you affect load capacity, handling, ride height, etc.
(2) More shocks doesn't mean it rides better. In fact doubling up shocks will make it ride worse unless you put two shocks each with half or less the valving of the stock replacement single shock.