402 isn't that high. I'd say give yourself a little more slack and limit it to 500. Your unwraps on the right of your last image look fine, those are all using one texture image right?. Mirroring the UV coordinates to save space is always good. On the chest piece, what I'd do is straighted the left and right edges…
The legs are lookin' a lot better. If you really must reduce the poly count, remove the nose and ears. They are very small details that won't even really be seen. Sorry, unfortunately I've never come across any good basic texturing tutorials. I mainly learn from checking out the Low Poly thread which has a lot of good work…
You're sacrificing some really important shapes while leaving hardly-noticable detail intact. For instance the guy's upper legs are extremely thin and he's lacking any hips, but you did leave in the slight indent on the inside of the feet. The wrists also need some thickness, and I'm not sure of having a separate…