In short:
The Law of Resistance only increases the Truespeak DC by +1 for each subsequent successful utterance. Resting for 1 hour removes these DC increases. The Law of Sequence does not stop you from using the same utterance before a currently-running instance of it ends, but successfully speaking the utterance again ends the running instance of that utterance. In addition, you can dismiss any ongoing utterance of yours with a duration outright as a standard action that does not provoke an attack of opportunity. Dismissing an utterance does not require a Truespeak check, but you must mee…