I generally agree, HecatesLover! Good analysis.
The laboratory bonus for explorers might be viable if it restocks them out in the field. Not having to return 30 tiles with your 2 starting explorers is useful. Then again, due to upkeep and lost time, it might be better to just construct new ones and destroy the "empty" ones. Or use them to block the excavation site from access by the AI.
About the 10% worker rate from Recycler, I'm very curious about rounding. Many tiles don't need 10 turns to be improved, especially when you have another bonus already (e.g. from being PAC or the prosperity virtue). It also depends very much on whether all those stack multiplicative or additive.
About cyonursery, I tended to have 1-3 specialized military cities with high production. But apparently, there are no XP buildings anymore, so I guess only the buildings that give +production for units would give an incentive to centralize military production. But there aren't many of them, either (repair facility, anything else?), so we will probably build units anywhere, even in low-prod cities.
In summary, since 5% is always weaker than 1 prod if you don't have at least 20 prod, I'd say the straigh prod bonus is better (it affects everything).
Disagree on the vivarium. I will build it if I need food, especially in dry areas where there is none (desert bonus!). So this is the "bad soil" counter, and I would never want to dilute that role. This will also help cities to get started at all, so it is very powerful if rush-bought for midgame expansion.
On all others, I fully agree.