A key point for my advice: I'm not always right. This is "to the best of my knowledge".
Consider condensators "vents that don't heal". So for a advanced vent, it absorbs 12 heat and then "heals / vents" 12. If you watch its health, it will effectively "damage 12 / heal 12". A condensator might take in heat based on reactor heat, but it will never "vent / heal". So if a 30K coolant cell takes 200 heat from the reactor, it will never go back to 30k. It will be at 29,800 until you take it out of the reactor and manually repair it.
Condensators will also never pass heat to a fluid reactor, for the same reason.
On reactors "per tick / per sec": The point is that it all happens at the same rate. Count all of the information on the wiki as "per sec" and you won't go wrong. or all of it as "per tick". Reactor Heat Exchangers pull 72 heat from the reactor per time unit, and will just sit on it.