Is this thread to discuss playability, historicity, or whether the naming of the civics fits within the broader scholarly literature?
Only the three that Hickman calls "F-tier" really need any overhauls. Even the ones called "C-tier" or "D-tier" above are valuable situational pieces for specific civs/regions. (Medieval meritocracy for China, Korea, and [sometimes] other parts of Asia? Sounds right.) You're also drastically underselling some of those "C-tier" civics like monarchy that are absolutely essential for small militaristic civs like Germany. (Although the constabulary could use a buff, there's no real reason for any more buffs.)
1.
Vassalage: Vassalage should let you maintain large armies but only to fight quick short wars before you go broke.
Needs a nerf because when my European civ (Portugal and the Netherlands excepted) should be switching to centralization, vassalage is still better. I would remove the free unit support
during wartime, add "no domestic trade routes" (from nobles running mini-economies in my territory), and remove the hammer from farms (never made much sense). During campaign, nobles wouldn't fund logistics, and kings often had very few revenue sources so campaigns were kept short.
2.
Centralism: The the whole point of why 16th, 17th, and 18th century European kings centralized power was to draw on tax (normally tariff) income to fund the creation of larger standing gunpowder armies and navies.
While adding modifiers to the capital makes sense in the strict definitional sense of the word "centralism"--rulers didn't really centralize power in the 17th and 18th centuries to make their capitals hyper productive

. (I would change it to +50% commerce and +50% wonder production [e.g. Versailles] in the capital.) Centralism should tie maritime trade route income to gunpowder and naval unit support in some way to allow for the huge standing armies and global wars of the 18th century. It probably should also produce extra unhappiness (represents revolutions in Europe, dissolution and re-unification cycles in China) and + commerce on mines and plantations (monarchs in Sweden and some non-European places that didn't have overseas colonies began to centralize control over other revenue sources, often mining and cash crops). Centralism should definitely synergize with colonialism (encourage you to go found colonies) and monarchy (necessary to combat the extra unhappiness).
3.
Tolerance: This needs an entire overhaul to be viable. I would add having it allow you to receive persecuted immigrants from neighboring civs that are not running tolerance or secularism and that are in the same region/religious group. That's how Protestant civs such as Prussia and the Netherlands used it in real life to grow their populations fast, and that would give it more synergy with America which spawns with it (for some inexplicable reason).
This makes it extremely powerful for a short time, but also puts a hard time cap on its usefulness once other civs in your culture group go tolerance/secular.
I do also think some names should be changed to bring them more in line with generally accepted scholarly convention:
1. "Despotism" -> "Personalism" (Most dictators don't use violence as their go to. That is true today and was true in ancient times. I think this is a hold over from base civ.)
2. Also, is there a 6th gov't that is missing above? Generally, autocracies are classified by political scientists into "monarchies," "personalist regimes," "single-party regimes," and "
military regimes."
If there are only 5 governments I would re-orient state party away from conquest and focus it solely on espionage which is already very useful. (Make Lubyanka require state-party to build.) Then I would create a new "military regime" (name it something more creative) government that is synergistic with revolutionism but is
not conquest-oriented (kind of a nichey small modern civ govt like revolutionism is for Latin American civs). I leave the details to men and women smarter than myself.