Your list is disasterously low on anti-tank firepower and will be utterly decimated by any list with a fair to high amount of vehicles in it. The two most obvious places to get more AT firepower is to give your Hive Tyrant a Venom Cannon along with his TL Devourer and to take some Zoanthropes.
Also, you've put a tremendous amount of your points into Hormagaunts which are pretty useless in Escalation missions so if you're going to be playing any games using that rule you need to rethink your army concept.
Here is some unit by unit commentary:
1) As I stated above your Hive Tyrant should really take a Venom Cannon along with his Devourer. The Lash Whip/Bonesword combo is a pretty useless choice, especially considering how many points it costs.
2) Tyranid Warriors are a pretty poor unit for the amount of points they cost. If you just need Synapse you're better off going with 3 Zoanthropes w/Synapse & Warp Blast (and they give you AT fire too).
However, if you're going to stick with Warriors drop the Toxin Sacs as they don't do much statistically for most of the targets you're going to need help fighting in CC (since rending attacks do most of the unit's damage). +1 WS actually gets you more statistical kills against MEQs for less points (2 points per model), but honestly I'd suggest not taking either to help keep the unit's cost down.
3) un-upgraded Hormagaunts actually struggle to kill MEQs and since a huge chunk of your army is made up of these units you're going to have a hard time winning games against MEQ opponents. Fully tooled up Hormagaunts (+1I, +1WS, +1S) can actually decimate MEQ units if you have enough of them.
If you want to stick with Hormagaunts as such a big part of your army (i.e. you know you're not going to ever play Escalation missions) I'd suggest going for the full upgrades and just drop the number per unit to compensate.
4) Your Carnifex should be a standard Gunfex (Venom Cannon, Barbed Strangler, +1BS, +1W). See my article on equipping Carnifexes in the articles section of this website for my reasoning for that claim.