2 - Sliding Trip/Kick Animation: When sliding on the ground you can hit an enemy (which I think knocks them down) but it would be way cooler if you could slide and trip/kick them over.
Actually, you can already slide kick in Crysis 2. Just press the melee button while sliding and Alcatraz will perform a kick. I learned about this a few months ago.
3 - Picking up Guns/Ammo Animation: This one would of coarse be brought back from Crysis and I think it should. It really added a whole new level of fun to the gameplay. I remember having to simply make a plan just to run out from a hiding spot to pick up a gun or get ammo sometimes and it was great to see the animation.
Great idea, I'd love seeing this return in Crysis 3.