Construction yard provide incentive to build more cities since its 3 production eats 3 minerals, so for city that specialize in production, you need more mineral gain to sustain it.
Edit: Did some more games
Harvest food/mineral usefull but need a serious boost, since at the moment its mainly situational and its lose its usfullnes preety fast, bad part is that its mainly usefull on normal pace.
My tests with this action was mainly aimed for fast first city expansion and fast resource aquisition, didnt test it in mid and late game on this tests since the output is just to low compare to improvments + buildings.
Fast first city expansion was to build 2 formers at the start and rotated them with one harvesting and one building improvments, dependable on city needs.
Fast resource aquisition was for expanding with new city in early game 2nd to 4th city, put it near special resource and put a former on it, this allows city to work on diffrent square while still providing special resource bonus + harvest bonus.
Both of this strategies did work but comparable to other games it did heavily sit on my money income even with panel park feature, compare to just spamming farms and mines, thats the main reason why i think it would need a big boost in its effectives.
Having less features means you have less places to defend at the start which is a good part, but the ammount of formers you need to actually compare resource gain to features is quite imbalanced, like i said in the earlier post each former need his own defence especialy in early game, and this still sit on money income and ability to build more formers/units/buildings.
This is all done and compared with normal pace, as for epic and marathon i still need some more tests but the game is very diffrent with diffrent pace, found out that normal pace is much more easier than the epic one.
Long range harvesting ( out of faction borders) was a disaster for me in early game, it require to many units to defend the harvester and the gain from even special feature with normal feature to boost it was just to small to justify it .
Thoughs, Theories, Suggestions:
Harvesting action is one of most valiable features if boosted, it can be used to stop mineral crisis in late mid/late game since by that time player have both ability to defend and pay for formers without it heavily effect his money income. Long rage harvesting is valiable to but it would need some more boost prefebly from some feature, something like agressive evolution pathogen emmiter that would boost food prodution to be harvest but would have some bad effect like a chance for plats to get aggresive and eat the former , or heavily overclocked nuclear generetor for mining that can blow up,generaly something you cant or would not want build within city borders. High risk, high reward.
Also another boosts for this via research would be nice to or only from research althrugh then it wouldnt be to usefull at early game.
New Features:
In general i think they got decent synergy between them which is balanced preety nice on the thin line, exept the habitat one.
I had some more tests with habitats (normal pace), and compare to what i writed erlier i was wrong alot

It is the one and most OP feature and im not sure if this should be deleted or more heavily penetialized, only thing that make it not to much Op is the time for it to be effective.
Not only you can speed up your city growth and steer the tide of new colonists where you want them, it makes cities not to loose to much morale from overpopulation and genearaly makes them jack of all trades in long run. Im still not sure if i should build construction yards or just spam habitats.
The pentaly of -2 gold its only painful in early early game after the feature was build, but some turns later you get that more than that 2 gold back, you also get a additional worker, extra border and so one.
I did some math and in general habitat cities are only a bit worst than purly specializaded in that barnch.
All this above is only my opinions and experiances, which may or may not be wrong and all that other stuff
