The heat outside is somewhat your problem. Find a hill and try the engine braking with the A/C on and try it again with it off. See what happens. The A/C can make the engine brake act weird.
So far so good! I do need to adjust the hinges a bit but the latch has been fine. Just have to make sure the door gets shut all the way.
On the end of the latch end of the rod it connects to a vertical link. That link wants to be just touching the body of the latch with everything at rest...
That isn't an uncommon problem. The best fix is to get a metal rollover valve to replace the factory check valve. Then re route the vent line back away from the cab. And while you're at it add a cheap inline fuel filter to the end of the vent line so your gas tank isn't sucking in dusty air. All...
The problem is the link between the outside door handle and the latch. All you have to do is make it a little bit longer by taking some of the two beds out a bit. It needs to be about a mm or 2 longer than it is.
Dealers aren't paid to fix problems. They are paid to change parts. The new parts...