The rules for solo play say that you go through the Action tiles "until the action you want comes up". Does that imply that I should be deciding on one specific action that I want to use, then I must flip tiles until that one action comes up? Or can I, e.g. have 4 possible actions I want to take (1 for each pawn), and flip until one of those comes up, use it, then continue flipping until the next useful one comes up, etc?
I don't think there's much of a difference. You don't have to "declare" which action you are looking for in the deck. I mean, who would hear you?
I'm pretty sure you just flip until you get something you want to do, do it, and then rinse and repeat.