Agree with the above poster, Grots are kind of a waste. For roughly the cost of a unit of 3 grots and their Raider, you can get a unit of 2 Talos. Stick 'em with the haemies and you've got at the very least a good Distraction Carnifex. But honestly you're better off filling the Raiders with more Wracks to get ObSec, Ossefactors, and as much if not more melee punch with Acothyst upgrades.
Give the Wracks Ossefactors, and the Acothyst an Electrocorrosive Whip or Agonizer if you can afford it.
I don't think the dual cannon upgrade on the Venoms is worth it. They're transporting melee units, so you're paying 15 points for 2 poison shots a turn. That's .444 repeating guardsmen killed per turn. For 15 points.
I'd drop the Blast Pistol and Lance from the Scourge, and give them Dark Lances instead. For one, your blasters are completely wasted in close combat, and anything but a vehicle will kill your Scourge in close combat. And at a tournament, no opponent is going to give you an opportunity to charge an important vehicle with deep strikers to tie it up. Better off keeping them at over 30" away (6" move plus bolter range) with Lances.
Yo ho, yo ho, a drug-fueled BDSM space-elf pirate's life for me!
Can I get a Roll Tide?