Hi I run a 1998 Chev 1/2 Ton. with stock E rated tires and air bags.stock everything else. I use 4wd frequently to get where I need to go. Always over weight no problems. 120000 km from Alberta to Baja 4 times. I am a middle class dude who wants to retire early ( Read not wealthy) So I am very careful to determine needs from wants. 350000km on this truck. No real problems with suspension. Door handles are another story . I think you will be fine with your rig and you can save some money abstaining from a new whiz banger heavy duty truck.
this said when I need a new truck I may as well get a 3/4 ton or greater.
I would endorse a sway bar though … even My air bags don’t prevent sway.