Have you replaced the plastic bushings on the striker bolts? Not having the bushings makes the lift gate not latch properly and adjusting the bolts to get the gate closed all the way can damage the latches over time. If you are breaking the handle there is a problem elsewhere.
Remove the inner panel and replace the lift gate handle. Lube all linkages inside the gate with spray Lithium Grease. Inspect the latches for wear or damage, if they are good lube them, if not then replace them. Inspect the Hinges for wear as the lift gate is very heavy and the hinges are a known wear point, Adjust the striker bolts so the lift gate latches properly (both clicks on both sides) with the gate not touching the gasket and the gate proud of the body. The lift gate should open as easy as the doors, they use the same style of latch.
When the lift gate opens and latches easily adjust the striker bolts forward to bring the gate into contact with the gasket and into alignment with the body. If you make contact with the gasket and the gate is not flush with the body and adjusting the bolts to bring it flush makes the gate hard to close and open the gasket is causing problems and should be replaced.
Good Luck
