What is happening here? The two holes on either side of the rear end cover. The left I marked with a paint marker cause I thought it was sliding and sure enough it is .

 

That's something you definitely need to address. You really don't want half the axle abandoning you at any kind of speed. "Pants Filling" wouldn't even begin to describe the excitement level.

Need to find a shop that can press the tube back in, then put a bit of a weld on that hole to keep the tube in place.