I was thinking about the Tyranid list the other day and surprised to see there aren't more suggestions of how to change it.
Just some random thoughts...
1. Reduce the cruisers to a base point of 60pt
2. Since cruisers are growing to be Hiveships, have them be independent of Synapse. Leadership 6 for purpose of command checks, still makes the Hiveship synapse potentially helpful.
3. Allow cruisers to purchase a Synapse addon, maybe shorter range? 15cm?
4. Allow escorts to fall back to Leadership 6 for Insticctive Checks if outside the Synapse range, they're likely to fall back on instinct, but have a chance.
5. Eliminate the requirement of Hiveships/Escorts (I dislike any fleet that requires escorts or battleship class. Dark Eldar, Tyranids, SG Tau, etc Just a mechanic to sell more minis)
6. Oh, give the cruiser launch bay capability if the requirement of Hiveships is removed