A player's reaction to receiving a redshirt is based on the player's class, his recruiting position rank, and how he ranks on his team (so if he's one of the worst on the roster, he is more likely to accept it).
Also, his reaction (whether he's upset or accepts it) will always be the same as it was the first try for a given season. So there won't be any benefit to removing and applying it multiple times.
If you do apply the red-shirt multiple times, and he's not happy about it, his work ethic decline will most than likely be much more drastic.