I think the trade is worth making. I think Sizemore will have a great season this year. Kinsler is strating on the DL and that worries me. He always seems to be a little overvalued and finds a way on the DL.
I wouldn't do this deal. I know Kinsler is injury proned, and Sizemore is in for a bounce back year, but they are both potential 30/30 candidates (with Kinsler having the better chance of it) and Kinsler's injury woes are balanced out by his extreme value at a thin position in an AL only league.
Also as much as you man welcome Grady, your OF is already very strong, and I just can't get past the fact that the drop from Kinsler to Willie friggin Bloomquist compared to what the jump from either Snider or Chris Davis to Grady? I just don't think you make up enough value with Grady then you do losing Ian. Also with the SP, Sauders gives you nothing more then 12-15 QS, his Ks really mean nothing as he will just barely top 100, and his ratios will hurt more then help. At best I see him being your #6, with a possibility by seasons end being your #8, how? I see Anderson-1, Lackey-2, Price/Gio interchangeable at 3/4, Dice-K-5, Morrow-6(with the potential to be your #3 seriously), Meche-7... Saunder had one big year and hasn't done much of anything any other year.
I stay with what I have and ride Kinsler for all hes worth while healthy... grab the best 2B available for Crisp and roll with what you have...