Hello, you could try to put little bit of plastic on the black dot and glue it in on home button and power one. About the screen I don't see anything strange.
Hello, It could be problem with flex cable, or connector on motherboard. If you've got the old display you could check it. When you gonna put old one with working touch screen and it will work it's something wrong with flexcable on the new display. -You could check too if flex cable is fully connected. -You could try to recover ipod with itunes