Just add one obvious change. Like the old days the surge larva ONLY appear if the queen is on Ovi
That way the marines can kill her, or drive her off it to stop the larva.
And queens can have the option of playing supportively (on ovi giving reinforcements) if its a siege. Or just disregard it and go nuts combatting when it doesnt matter.
And then the spawnpool manipulation sillyiness wont even matter