So me and a buddy are entering a doubles tournament at our local GW and the restrictions are standard force org, 1 HQ/1 troops each minimum (so total 2 HQ/2troops minimum between us), and 850 points max each. There are no restrictions on the armies that can play together so im playing my tyranids and my buddy's gonna play his iron hands space marines.

The only things i know for sure that are entering are: 2 crimson fist players, 1 iron warriors player (is taking 2 vindicators), 1 eldar player (lots of war walkers/warp spiders), 1 tau player (lots of crisis), and 1 guard player (lots of troops with lascannons and what not). There will be more armies but that's all i know so far.

Anyways here are our lists, tell me what you guys think:
Hive Tyrant
-Acid Maw, Adrenal Glands (+1 I), Adrenal Glands (+1 WS), Flesh Hooks, Implant Attack, Toxin Sacs, Toxic Miasma, Winged, Scything Talons, Scything Talons, Warp Field

11 Genestealers
-Flesh Hooks, Extended Carapace
10 Genestealers
-Flesh Hooks, Extended Carapace
19 Termagants

Heavy Support
-Synapse Creature, Warp Blast

-Epistolary, Machine Curse, Null Zone, Terminator armour, storm shield

Sternguard Veteran Squad
-Space Marine Sergeant: lightning claw, melta bombs
-3 with combi-meltas, 1 with bolter
Drop Pod
-Deathwind Launcher

Tactical Squad
-Space Marine Sergeant: power weapon, melta bombs
-extra armour, twin-linked lascannon

Heavy Support
Thunderfire Cannon
-Extra armour

His techmarine from the thunderfire cannon can give one terrain piece a +1 boost to its cover save which we'll use with my genestealers to help them survive getting across the field. He'll drop down first turn with his drop pod and destroy a tank that'll be a threat to my nids and then provide cover fire while I get across the field as quickly as i can and destroy things like heavy weapons squads that could destroy his guys. Basically he provides cover fire for me and I prevent things from assaulting him. We have lots of things that'll go through various armor saves (especially rending and my hive tyrant) and against swarms like orks the thunderfire cannon and vindicator will do wonders. Also the null zone will help against pesky things with invuls so that my tyrant and his powerful guns will have a better chance of killing them in one turn.

Let me know your guys' thoughts/ideas and criticisms. I know already that we'll have to be careful with our scattering weapons but with some planning that shouldn't be too bad.