Must say I found your original post baffling with spurious reference to things not working which you don’t mention having ? Don’t see what the purpose is of mentioning the dimensions of you old tv , how is that relevant ?
If the tiles are mounted on plasterboard it will all need to come out . Grout is water resistant not proof so background will get damp .
Personally I would avoid tiles in a shower .
If it’s catching bottom the it needs moving over at top , not lifting. You would need to remove screws in vertical slots as they will prevent lateral movement ( Top and middle hinges), loosen only at bottom hinge if only slight movement required.
Except your post shows it was edited .Dishwasher does not need hot water feed to rinse so waste of time buying one , it also needs specific temp for different wash types which may mean the incoming water may be too hot leading to longer wash time as it waits for water to cool.