Across my Jeeps, Toyotas and Fords I've never had a suspension kit that made my highway or off-road driving worse or less reliable from OEM. I live in the Rockies in a rural state with high speed limits and a small budget for road repairs so cornering, pothole handling and corrugation compliance is is weekly and rather important to me.
Strong mid-level shocks with the valving style you prefer can hit that goldilocks zone of great off-road characteristics with better on-pavement or high speed performance. Bigger shafts, better heat dissipation through aluminum bodies and increased oil, bigger stroke lengthes, and superior valving will all outdo most stock shocks. Doing your homework on digressive vs linear vs progressive shock valving can make a difference. I really liked digressive valving on my IFS rigs (mid-tier Bilstein and Icons), but prefer linear on my Jeeps.
For #2 if you land up with an IFS rig, I'd get longer control arms as part of a kit, they increase droop. Arms will also widen that goldilocks zone for handling if you lift the truck, they help maintain stock like suspension travel paths. Get coils and leafs that match the load carrying you'll be doing. They'll allow your shocks to extend better on rough routes or high speed bumps.