#2
First track is interesting, like Industrial Funk.

The rest sound like a little like they're stuck on the intro. The riffs need to evolve into something. Think "Intro, verse, chorus, bridge, verse, chorus, verse, end".
#4
I think the riffs and stuff are great, but as the guy above me said, you need to take these songs somewhere. You're staying with the same melody for the whole track. Regardless, if anyone points that out, you can just be like "It's recorded pretty well" and they'll be like "k koo".