I really like the list and might even steal the Cybork Idea for myself (if you dont mind) as i face lots of nids and Kornate chaos. Do the shoota boyz really work that well that you want 3 mobs of them? Lastly, this isnt so much green tide as Exessive dakka. The idea behind green tide is A) Lots of boyz and B) Lots of Choppas. For me the use of 30 lootas kind of hurts that image expecially at the lack of nobz.
Feel free to use any ideas from this list for your own, that's part of a public posting. As far as the shoota boyz go, they're much better than slugga boyz IMO for footsloggers because they're effective from 18" out instead of only melee range. And effective they certainly are, easily outshooting their points worth of anything else. And better yet, they still rock at melee. The difference between 2 attacks base and 3 attacks base is small but the difference between effective on turn 2 vs. effective on turn 3 is very important.
As far as what is green tide, I'd class that as any Ork list that bases itself around large footslogging mobs. The bread and butter of this army is big mobs, but uses infantry and upgrades that produce a little more synergy than just taking max boyz.