Quite an interesting list, though I'm not sure how well it'll do...
There are some things that definitely need some attention:
HQ:
Your warboss needs either 'eavy armour or, preferably, a cybork body. The 6+ armour save alone just doesn't cut it.
Troops:
Drop the Kombi-Rokkit (it sucks, due to BS2) and get a Boss pole - it's a must! For the same reasons, you might wanna get rid of the
TL Shoota as well. The only weapons upgrade that really has a realistic chance of actually
doing something is the Kombi-Skorcha, as it ignores the Nobz sucky
BS. Give the Waaaghbanner to one of the guys with big choppa and give a second kombi-skorcha to the guy with the
PK to keep the wound groups intact. At least that's what I'd do
Also definitely drop one of the grotz and a runtherd. That's 13 points saved with practically nothing lost.
Heavy Support:
You might want to consider giving grot riggers to your wagons. Sucks to be immobilized in turn two with no way of fixing it.
Other than that, try it out and see how it goes.

The one thing you really miss is some more anti-tank power...