I had the same issue with the ball joints sliding off their axles. I think it's because the bootleg axles don't have any friction ridges on them. Either that or the mold is just off. The worst part is the upper arm connection to the shoulder. It's just a very wonky design.
I did not have the issue with shells popping off the bones though. I found all of that stuff to be really good quality in each of the ones I bought. In fact this one is the only one I didn't buy from the set.
Getting them to balance is a little challenging, because the way they attach their custom pelvis to the hips of the CCBS torso frame is poorly done. But I didn't think it was that bad.
Unfortunately I think the weak axles are a recurring trend. I watched a review of a similar one and it continually fell apart as he was reviewing it. I think the shells and limbs are fine, however.
@ReeseEH This has been my experience to a T. Even going back to Hero Factory sets that I bought last year.