I would add that any possible gain you would get do to the extra water and fat will lost as soon as you diet to take off the water and fat anyway. So it should be used for bulking just so you less to cut.
it will decrease the water and fat that you would gain from higher insulin levels. This in a small way may decrease some muscle gains, as water and fat allow you to move heavier loads, but then you would also have more fat to shed. its a trade off of sorts.
though if you weigh it, the overall benefits are better with use, as less fat from bulking to lose.
no, you will still get the carbs and their associated "muscle centered" water (4g water per 1g carbs), you just wont get the extracellular water that comes with insulin.