I don't have mine on the stands as they are quite solid on their own. You have to really raise those stands to get a good grip but I agree that along with the hands could be better. Its the loose grip index finger that's the issue. It looks nice but just not very practicle. Though if you press the sword handle into the pinky and ring finger, the hand grips just fine.
I do disagree with the posing comments though. I posed my just fine (see a few pages back) and good luck finding figure with that level of muscle mass that can pose well and not have unsightly joints. None of the Arnie Hot toys pose particularly well.
Hot Toys Thor could never hold his diecast hammer as it always made the wrist flop down and even his entire arm in some cases. Hot Toys Gladiator Hulk cannot even hold up his hammer up and that's a ratcheded joint.
To solve the Havoc Staff problem, Just rotate the peg so it cannot rotate anti clockwise.
Merman looks like he has very different hands and his trident is not so heavily I would think so there should be no issues there and any potential paint rubs can be easily avoided with just some clear plastic between any rubbing surfaces.