Yep that's true you can try 3 attacks if you want, first check normal, second -5 (-4 if agile), third -10 (-8 is agile). Only one with sneak attack though.
There shouldn't be a limit to sneak attack on a rogue, as long as your target is Flat footed. Unless it specifically states in the action, like Double Slice or Flurry of Blows.
Question, since Gray & Marta are talking to Sam, while me and Gicicero are searching the Ringleader's wagon ... do you want perception rolls from us to search it, or should we just assume that as a group everyone is participating in every scene?