I wouldn't mind seeing old weapons one bit. CoD4 M16A4, CoD4 MP5, CoD4 AK-47, WaW M1 Garand, WaW M1 Carbine, MW2 UMP45, MW2 MP5K, BO Galil, BO Spectre M4; that's just my list though (high hopes, fingers crossed, blah blah blah).
XG21G2D4 Figurines, T-shirts, posters, keychains, coasters, **** pillows, et cetera.
No. This is a futuristic game, so it needs futuristic guns. The only guns i can see being in this game is the Spectre and G11. No cod 4, WaW, mw2, or mw3 guns seem like they belong in this game because they just wouldnt feel right imo.