After two battles, I have some constructive criticsism that I think might help you. I don't think these are big changes.
1. Lictors: bane of Imperial Guard - Not only do these guys have the phermone trail to help bring in your units, they also are str 6 and have a shooting attack now! Strength 6 is perfect for assaulting all IG tanks since they all have rear armour 10. You can also use them to act as a homing beacon for your deepstrikers (Trygon/Mawloc/spore launched gaunts/gargoyles). If you want to use them as a homing beacon, go to ground in cover with that 2+ cover save and they should last. ** Can lictors start on the table and not in reserves? If they can, this is one way you can get that +1 to reserve rolls right away.
2. Good things come in pairs - As a guard player, there is one basic rule to always remember when it comes to tanks. Never take only 1 battle tank. It will draw all of your opponents anti-tank weapons. The same applies for Tyranid monstrous creatures. Although your list did have more then 1, there was never more then 1 on the table at a time. You either want to start with both of them on the table or both deepstriking. If they both arrive on the same turn, your opponent now has to do ALOT of wounds or be assaulted by at least 1, if not 2 beasts. Assuming its a Trygon and a Flyrant, that is 10 T6 wounds that need to be done. Should they both survive, you can probably take out whatever units are toting the weapons that can damage them.
3. Consider dropping the Flyrant in exchange for the Hive Tyrant that can add +1 to your reserve rolls. Dolan said those wings cost 60 points. If that is true, you can purchase a squad of 10 gargoyles for that price or beef some of your broods. The gargoyles would be another deepstriking unit that would benefit from the +1 to your reserve rolls. This would let you move forward with your Zoanthropes where they can be in range with their weapons rather then sitting back holding gaunts in synapse on an objective.
I think you have a great idea with your list. My marine list is also heavy on deepstriking and outflanking units. It also suffers from the same weakness yours has though. If you can get them all in early and together, you can wreak havoc on your opponent. If they come in piecemeal, you are in trouble. You just need to find a way to make use of the units your army has that can ensure you get them on time.