Hmm... the youtube videos show the gas cover as very easy to remove - easier than an SKS. Just rotate a sight knob and lift it off - is yours not working like that?
The mag release is supposed to be like that. It's meant to be operated by Chinese soldiers with thick winter mitts on. It's not meant to be the same catch as an AK, though you could probably put an AK catch on there, I suppose?
The receiver cover is supposed to be thin sheet steel - what did you expect it to be like? It's not meant to be a heavy machined part like an SKS, it's meant to keep dirt out and be light. The gun works without it even installed, by the way.
It's also made of sheet steel, so if you are thinking of a milled AK, then this is a very different thing. I've had both milled AK's and stamped AKMs. The AKMs felt inferior in every way when holding one, but were strangely more reliable than the milled guns I had. Both shot about the same. I don't have my T81 yet, but I expect it to be a lot like a stamped sheet steel chinese AKM in the quality department. So not great, but reliable, functional and accurate enough for its purpose.