I think your list is good until I get to the stormboyz. In my opinion they are just over priced orks with jumppacks. With the new run rule regular orks on foot can almost cover the same ground that stormboyz can. I would drop them in favor of 3 more deffkoptas, a loota squad or another squad of regular boyz.
Grots they just ain't what they use to be. For their price I would rather take a small group of orks even as a sheilding unit. Armed with shootas they will atleast be a threat to the enemy.
All your troop mobs need Nobs in them with boss poles. So that when they start taking damage and get below fearless they can stick around.
The killa kans I like to have them all armed the same in a squad or atleast armed with big shootas or rokkits. Since kans are crewed by grots they have a higher BS than dreads so take advantage of the shooting. Scorchas aren't worth it.
Zzap guns to me are the least favorite of the choices. They cost the most in points. You have to roll to hit with them they don't auto hit anymore and then you have to roll for the strength. So even if you hit you may do nothing to what you hit. The battery also has the possiblity of killing one crew member so you have spend points on extra crew memebers. Zzap guns mostly only useful against armor terrible against troops. I like kannons for them being cheap and you can fire a high strength shell at armor or a blast marker at troops good for all around use and the same range as the zzapp gun.
Strip down the looted wagon to just the boom gun since if it moves over 6 inches you can only fire one weapon. This allows you to move the looted wagon at combat speed and fire the boom gun at armor or at troops. Big high strength blast template goodness.
Use the rest the points for other fun and destructive things.