Well that black stain will prob not come off until he sheds again. It might help to get a babies toothbrush and give him a gentle scrub in the
bath every day. (it will also keep him
hydrated.) i would either rplace it with slate tile (from any DIY store, or a tile warehouse, very cheap) or just some paper towel for now. How has his eating/ pooping been?
If you wanted to over your set up in detail, we would all be pleased to help. How about the most basic questions, what UVB are you using, specifically the Brand (printed on the bulb), and what temps do you get. Also what are you measuring those temps with??