very rough concept
So one thing that really annoys me about the gorge is how weak he is. It may only cost 10 res, but for the almost painful movement penalty, the gorge should at least have some ability to soak damage. Currently it takes a level 0 marine 30 lmg bullets to kill a gorge. This really is quite unacceptable considering how slow the gorge is, its almost impossible to miss him. This usually results in any gorge who encounters a marine without having substantial fortifications established, dying very quickly, and without much effort from the marine.
A related problem, however, is the need to be able to rush an alien fortification and kill the gorge guarding it. The gorge can't very well need 3 LMG clips to kill it when its surrounded by its own hydras and skulks.
So my (very rough) idea to solve this problem is "scaling" the gorge with the structures he has active. Essentially what this equates to is the gorge using his own "body mass" to build structures, sacrificing health and armour for cysts, hydras and goo walls.
A freshly evolved gorge with no carapace or active structures would take maybe 50-55 lmg bullets to kill. This gorge would excel at in-combat healing. He could charge in with skulks, spamming heal spray the whole time, and be tank enough to stand a chance of not dying. However, he obviously provides no defensive benefit to his team, nor does he save the comm res by using his own cysts.
The gorge could, however, choose to rather defend key points, like harvesters, by dropping hydras. Each hydra he drops might reduce his overall health by 5-10% perhaps. After dropping 3 hydras he might have slightly more health than the gorge currently has in build 207, after dropping 4 he might have slightly less. This gorge would choose to stay by his hydras, being protected by them, and ensuring that they stay alive by healing them constantly.
Another player might choose to help the commander expand, should he need the assistance. Such a gorge could run around expanding the infestation with his own cysts, each cyst reducing his overall health by 2-3% perhaps. Such a gorge would primarily be expanding to nearby res nodes, and healing up harvesters. He wuld have enough health to survive for a short time against marines, but no real ability to confront them, resulting in him trying his best to run away.
A really cheesy player might go gorge and drop as many hydras as he possibly can (maybe 6 or 7, though that could be a few too many). However, this player would be so weak that he would be killed in 10 or 12 lmg bullets. This would mean he wouldn't even be able to support his hydras on the frontline, and would be forced to remain in the secure hive room (and even that may not be secure enough for such a weak gorge), healing up upgrade structures and other boring stuff.
In this system, the gorge wouldn't be strictly limited to x number of hydras, y number of cysts ect. Instead he would be given a certain number of "resources" (in the form of health and armour points) which he can spend where he likes.