Few wording questions: Does Participant Observer allow you to roll Perform checks with twice your Charisma modifier and your Intelligence modifier? Does it let you make Profession checks as if you were not untrained?
And now, an access concern: From what I've seen, Scarlet Throne is the warlord's Thing, and using it in other classes is frowned upon. Would you say swashbuckling is a part of this class's identity?
And finally, a concern with the capstone: You know you're breaking the "rule" that you can't add your ability score to a statistic more than once, right? (Personally, I'm opposed to that FAQ, but if I don't bring it up, someone else will.)
Other than those concerns, I like it. Pretty nice "clever vagabond" identity.