Yes, you have plenty of Synapse. At best it will take a couple of turns for your opponents to kill both your Hive Tyrants and then you still have 3 Zoanthropes you can safely hide behind your Carnifexes.
But, I'm not sure exactly how this is more of a "balanced" feel of a Tyranid army. You still have 7 Monstrous creatures which most certainly qualifies this as a Godzilla list.
The only thing you've really done is traded in some versatility (by removing the flying Tyrant for another walking one and not taking any Raveners) and made it a bit easier for your opponent to kill your Godzillas (by not taking +1 Wounds on your Gunfexes and not taking any Tyrant Guards for your Tyrants).
In return you've gotten a whole mess of gribblies.
Your games are still going to boil down to whether you can outshoot your opponents with your Godzillas, but you've just made it easier for your opponents to outshoot you (by making it easier to kill your Godzillas).
The fact is, you don't need 3 squads of Genestealers (two should be plenty to fight off any chargers) and they don't need Extended Carapace (since they should be hiding behind the MCs until they are needed).
You also don't need that many Gaunts, although it doesn't really hurt to take 'em but you definitely would want to split them into four units if you take my advice and lose one of your Genestealer units.
I'm not totally against taking two cheap Tyrants as you have. You lose the versatility of the wings but you gain another Venom Cannon. I just think if you're going to go Godzilla then you should definitely push your T6 wounds. . .that's the whole point. Taking the +1 Wound on the Carnifexes can even be dropped in a pinch, as opponents tend to target the Dakkafexes first anyway.
But not taking any Tyrant Guard with your Tyrants. . .well, that's just criminal IMO. They are such a good defensive upgrade for the points.
I'd personally suggest:
1) Lose the 3rd Genestealer unit and drop the EC off the rest of your stealers.
2) Split your Gaunts into four broods.
3) Buy 2 Tyrant Guard for one Tyrant and 1 Tyrant Guard for the other.
4) Buy +1 Wound for both your Carnifexes.
That should come out to just about the same amount of points. You will have greatly improved the survivability of your MCs without sacrificing your ability to counter-charge (remember that the Tyrant/Tyrant Guard will also be able to charge in and help should the need arise).