You might want to do a bit more research before making a post about a mechanic. Here is some of the things you might want to add.
Allegiance delta is always between -.05 and +.05. You can't move it faster then that either way.
It does affect resources gathered, which is why neutral extractors are so powerful, they have no allegiance so they get 100%.
It does not affect HP at all, no idea where you got that...
Vasari get +damage in their own culture.
the rate is determined primarily by the number of culture upgrades you've got compared to the number of culture upgrades he's got
I have no idea where you got this from, maybe you ment culture tech upgrades? The rate is determined by the strength of the two cultures pushing against eachother. This can be affected by techs, planet bonuses, placements of culture buildings, capital ships in the gravity well, ect.
(Then you mention that HP and culture are not related...)
The Advent super weapon also should be mentioned seeing as it is a culture cannon.
Each race also gets some culture related techs such as Foreign Sabatage and Eyes of the Converted.
Good to see someone putting some culture info up, but you really need to finish your research before you mislead people.