I'm guessing you don't play much. The line of play etiquette is as old as the game itself, and is maintained on tour because many of the players use cleats which are much harder on the greens, and any damage caused by these cleats cannot be repaired without penalty. You see, it is a matter of 'scuffing' the green. Hundreds of players walk the greens every day, the prints they leave on the green will affect your putting in no significant way; even if it happens to be a member of your foursome. In much the same way, when a player balances themselves with a putter while retrieving their ball, they leave no significant mark on the green. And so to answer your question, no. Same goes for your edit. I'd recommend giving the rules of golf a read, or, you know, playing golf.