What I don't understand is how someone can say that playing a terraform is harder than a hybrid. The disadvantage of a terraformer is that aliens will attack you. However, you can combat this by expanding and the terraform civic. That civic should be the first thing you really push for on the tech tree. If you do, and mix it with planned, it's over.
If you are surrounded in fungus, I would suggest limited growth early on. Just because you can grow to size 4-6 doesn't mean you have to right away. When you are ready for that population, it will be there as fast as you want it. I tend to work 2-4

tiles anyways early on like rocky most or arid land to avoid growth. Maybe a 1

2

tile if need be. But working 1 mine will buy you time in the early game to get a good defensive force and maintain a decent PV-PA. Once you have that, start in with the formers going around chopping fungus down.
You have to be careful and look at the real balance in a game. A statement like "terraformers are at a huge** disadvantage because of worm spawns" is blanketed and vague. The statement does not reveal how that weighs against all they other aspects of the game. Worm spawns make it harder for a terraformer. Harder than what though, harder than a hybrid? No. Just makes winning harder. An actual obstacle, and the ONLY one that terraformers have to deal with. Their obstacle is more focused.
**Subjective there as I don't find it huge.
I can usually run a -3 PA and not worry about them. Anyone who says this is a HUGE problem doesn't build enough military.Usually your flame units will keep ahead of the -XX% you take vs. NL with their natural +XX% bonus and you can add in psi defense/attack. Realistically, a terra has an 80% chance of spawning near no fungus. Sure 20% of the time you will have fungus to deal with. If you WANT to run a hybrid economy, you have a 20% chance of getting a good start for it. As a terra locate problematic spawn points and take them out with armors - not flame throwers. 2 moves + collateral damage is more effective than 1 move and +20-35%. Tanks take tower bombardment once and come in for the kill. You can also use choppers but usually they cost more as there is no collateral damage on their part but they only have to receieve it once as they can bypass a tower surrounded in fungus.
Hybrids problems are all over the board. It's a good thing the AI is stupid because a Hybrid vs. a terra in multiplayer is just sick. You can compete in the early game in production by building a few mines here and there but in the long run, your gonna get overrun. Wonders are going to slip out of your hands even when you had the tech first. But mid to late game expect to lose the tech lead and be playing catch up the rest of the game. As by mid game a terra can tear through a wonder pretty fast and start really teching good. Higher population cities make more

Fungus causes 1

for every +1 PV it adds to the city. Then you have to take +2

in the city after that. This means That using fungus as a way to get PA/PV is a drawback as you will have to build infirmaries and such. You have to stay at +3 PA or more to reliably not have to worry about NL. At +2 you will still have problems often enough. And sharing a border with a terra With your PA at +2 (really even higher) can cause blooms in your area and have the blooms attack you. Sure you get bonuses against them and this isn't a major pain for you, until it has happened the 4th time in a row. And they get +50% defense and double movement often on the way to you whereas if they go to attack the proper target, the terra - no problem, just wait for them to step out of the rocky terrain tiles if there is any and you know they only get 1 move. I really don't see the advantage to a hybrid. All I see is people subjectively stating that the terra has a hard time with wildlife which to me suggests playstyle more than game balance. In short, they get moderate bonus vs. NL but strong negatives vs. economy... in a 4x game... Whereas terras get moderate negatives vs. NL but also moderate bonuses vs. economy in a 4x game.
Not to mention getting through the middle and early games as well, where resources to build an army are limited.
This statement holds true to hybrids for me. Working a farm-eden(s), and mines (preferably rocky rainy) is plenty of resources to build an army. And this setup doesn't even hurt PV too much. (For a terra) But makes a small city very viable for production. And you can do the same thing with energy instead of minerals. Just use more arid tiles instead of rocky.
When I played as a hybrid, it was quite a bit simpler in a lot of ways.
Could you expand on this?