Questions about the barricade.
2) Are we talking 'squeezing' as in the exploration mode thing that takes 10 minutes and an acrobatics check or are we talking 'squeezing' as in the difficult terrain stuff?
Side note, I just realized Bair doesn't qualify for the class feat he took (Raging Athlete requires expert Athletics) so he is taking Acute Scent instead.
Regarding Resist Harm, I assumed its description meant that if you use the reaction against an initial source of damage that also applies persistent damage, then the resistance it provides doesn't carry over into future turns, not that it can't be triggered by a particular instance of persistent damage. So if Adalan used Resist Harm against the acid arrow itself he wouldn't get any resistance to the persistent damage, but if it's triggered by the persistent damage then that's the "initial effect" and it works (but doesn't do anything against persistent damage from the same source in future turns). I certainly could be interpreting it wrong though.