Alot of hookahs don't break down like a Mya. Most are infact, welded together. I own a KM, and a Farida. Both have the same basic construction. They aren't churned out en-masse like Mya via hard machining. Of course every one is going to be slightly different, And the rigid edges I would say, are normal and perfectly acceptable. Honestly, I say multiple hose hookah suck. Mya is the only brand that I am aware of that has the hose check system for multi hoses. If you want a quality smoke from a KM, you can't judge them off of a multi-hose rig. Besides - traditionally hookahs didn't have the check system anyway. KMs tend to be traditional that way, like most hookah brands. You may want to invest in a set of brushs as well to clean your hookahs, Because if you think disassembling them is a must to clean them, we need to teach you alot more, sir. If I were you though, I'd return the multi hose KM and get a single hose. Also, some bar keepers friend will take the black shit off. Most hookahs that are made of brass/copper/whatnot get tarnished. That's all that is. KMs will require a greater amount of care than a Mya to maintain asthetic pleasantness. It's not a lazy mans piece. It's something you take care of, and showcase, like a shiny trophy. You have to polish that trophy you know. And the coal tray just sits on there. You don't screw anything on. No need. KM are infact amazing hookahs. Just have to have a higher understanding of different hookahs. Which others can elaborate on alot better than I can.