The scrambled Dmd is a ribbon cable, likely got jostled during shipping. Unplug ALL ribbon cables and plug them back in.
Based on the pics you were sent, doesn't seem like any of the defects you note were really highlighted. I've learned that You have to ask for very detailed pics, you didn't get any pics of the head or boards, that would maybe have deterred your purchase. Playfield pinholes can be touched up, but should have been noted. Hacked wiring is something seller should have picked up, that's not really acceptable. That said rebuilding a connector is not expensive or time consuming to address...a tech can do it in 15 mins or less and parts are pennies, literally. The chunks out of the cab are unfortunate, but again, you didn't get great pics and should have pushed harder for better pics...lesson learned. Rather than return it, which is a hastle and costly for both buyer and seller, try to work out a partial refund. New cab decals are about $250 (not including labor), wiring will cost you about a hundred to get fixed, so maybe $400 off would cover it. A decent player shadow at $2800 isn't terrible...assuming those are the only issues. If I am buying remotely, I often ask for a video before I make the drive.
I bought a TZ from Rob with a non working clock, he covered a new clock from Ingo. I've bought other games from him, no problem. Other times I've had to walk because description was different, I've learned you just need to ask for very detailed pics. If you don't get them, walk away.