I personally wouldnt trade J-Rich in this deal. You cant rely on Gil to play hard the regular season. He will probably return with the last 15-20 games, but hes gonna need time to get back into game shape too. I dont like this deal at all. It sounds to me like hes being extra cautious too when it comes to returning this time.
Definately not. You will miss out on too much production frm J-Rich while waiting for Arenas to return and when Arenas does return he won't be where he normally would be, so there production would be about the same then too.