First, Yes you can stack amino acids and Nitric Oxide supplements with creatine. I personally dont take NO supplements because i think they're a little pricey..but if you wanna give it a try, go for it. Some NO supplements have energizers included in the formula, so it gives you a little extra boost pre-workout.

Amino Acids are a good thing to start taking, i personally take Xtend, but theres TONS of amino supplements you could take. Some are pills, some are powders.

And if you're going to take muscle milk, i wouldnt take it postworkout. Only because muscle milk is a casein blend, and casein protein is meant to be a slow absorbing protein. After you workout you want to get protein and nutrients into your bloodstream as FAST as possible. And with a slow absorbing protein like muscle milk, you'll miss that so called 'anabolic window' you get right after you train because the protein cant assimilate into the bloodstream fast enough. So muscle milk wouldnt be optimal for post-workout..but you could certainly take it at other times throughout the day if you so choose.

Hope i helped a little.