If he's gonna be 100% healthy that should be about right. Also I think his range is very close between the 2 and 3 so he may go 45%FG and 42%3FG. D'Angtony said the other day that Gallo is the best 6'10'' shooter he's ever seen and in that morning practice Gallo shoot 23 straight 3 pointers.
If he can go 18-20 PPG and all other stats you mentioned I think he will open a lot of next year FA eyes. If he does that, Lee, Nate and Chandler(if they are still here) match or improve their last year stats and Hill and TD shows potential we might have some play off buzz. Then we can only sign one big name(Lebron, Wade, Bosh) next year and be a player again in 2011 market after curry and jeffries are gone(if we can't move them sooner.)