What am I missing, I can't seem to get the Mage Hand to interact with anything? It can't pull levers or pick up items. What is this spell useful for?
Nothing sadly, unless you like shoving people so they fly halfway across the screen. Really depressing for Arcane Trickster especially.
I'm really surprised TBH... Larian loves their shenanigans, and imagine the kinds of shenanigans you could do in and out of combat with a useful Mage Hand that could pick up, carry and drop things, pull levers, open doors etc. Even just from a strategic POV, using disarming attack and having Mage Hand safely whisk away their weapon etc.
I am not really surprised. Larian seems to want to force their ridiculous version of Shove on us, so rather than have Mage Hand do anything that is actually useful they have it doing that instead. The sad thing is that in the Wiki description of Mage Hand, it says it can manipulate and interact with objects. This should mean all the things you mentioned.
I am hoping they fix it eventually to at least add in the proper uses for it, but the cynical part of me says it will continue to be useless and they are using the data of how many times it is cast to decide that we all love their stupid Shove mechanic, rather than looking at where and when it is cast, probably by people expecting to use it properly.