Good questions, especially the last two!
Sheijtan is on the right track, but here is your official response...
spiralingcadaver wrote:
-how does the vitality track work? Under what conditions are effects/favor generated? Specifically, are there things that circumvent it, such as hazards, friendly (or neutral) damage, healing and taking damage later, etc.?
The only things that typically will circumvent favor generation from the vitality track are that model's own abilities where you have a choice to trigger them in lieu of generating the favor (
Second Wind,
Disengage, etc.).
Mentulus specifically allows favor from vitality tracks only. Hazards, etc. still cause the favor to be generated.
spiralingcadaver wrote:
-similarly, I don't know how it'd affect the game, but what happens if a model is killed by a lethal hazard (so you mark and resolve the rest of its vitality), and it moves as part of that? (IDK if there are any effects that occur when a model dies near another model, but that'd be the sort of case)
Typically the movement will be resolved by the time the lethal hazard triggers. All pushes and other effects from an attack are resolved before damage is applied, and then the damage would be applied at the end (once the hazard has already done its work). I don't believe there is anything that causes the model suffering the hazard to move afterwards at the moment, but if something comes up later, that ability should apply before the model resolves being defeated
spiralingcadaver wrote:
-are there limits to the number of times tactics may be used in a given clear turn, other than explicitly stated ones and of course any resources you can run out of?
Except for the stated limits (and Zephyri correction below), no.
The Zephyri
Blood Brothers tactic lost a pretty important sentence somehow (Oops!). It should have the same final sentence as
Ambush: "This tactic may only affect each gladiator once per clear turn." Note that because the cost causes a model to suffer damage, that portion of it affects them as well
spiralingcadaver wrote:
-(for ludus magnus) what's the bottom of the damage tree? Is it the lowest row, or is it the last box along a given path?
The lowest row. Hermes is good enough.