Twotrees Saphire Plus - Having some trouble

(Twotrees Sapphire Plus) This is my first printer and I got it of an auction for pretty cheap. It is used. I set it up following an online tutorials and got everything together as best I could. When I tried to do the bed leveling I ran into a problem. The corners don't match up with the bed. Center seems fine. one corner is completely off the bed and the other are two close to the center, while pressing the third corner seems to put it back to the center.

Problem #2 - The wiring isn't supported anywhere so it just flops around, sometimes dragging across the bed.

Problem #3 - After placing the filament tube in the extruder It seems to be locked in place and I cant remove it. I pulled on it but I didn't want to break it so I just left it. Should i just yank on it till it comes free is there something I have to do to release it?

(Also got a mars pro, that seems to be doing fine on the setup, currently trying the first print.)