Is it ever wrong to push all-in with best hand, when to take a card off as a "safety" so to speak.

IN a cash game, is it ever a bad play to push all-in if you think you have the best hand ?

Very complex question. I assume this is NLHE?

When in the hand--pre-flop, flop, turn, river?

What do you mean by best hand? The nuts? Or just that you think you are good compared to the others with live cards?

How much is in the pot, and what are the stack sizes of those with live cards?

What kind of a read do you have on your opponents?

But your question was, is it ever a bad play. Yes, it can be a bad play. If you are first to act in a multiway pot on the river and you have the nuts or strongly suspect you have the best hand--i.e. you have the nut flush when someone was probably drawing to the 2nd nut flush, or there is also a straight on the board, or you have a boat where there is also a flush or straight on the board and it seems that someone was drawing to it--you probably want to either check or make a small bet in the hopes that someone acting after you bets or raises so you can re-raise. If you just shove you may not get a caller or may get fewer callers or no raiser, and will end up extracting less value than you would otherwise. (Of course, in some situations you can make a shove look like a desperation attempt to steal the pot and get callers that way.)