Can they pick the usernames and any other information required to setup user records at your side from the LMS (ours or client’s) without prompting for authentication?

LMSs are limited in the amount of data that is pushed through from the games. Typically, the player’s name and if they completed the game is the only information seen within the LMS. For a more robust view of player data, the Analytics section within the Admin portal will capture more information such as questions answered correctly/incorrectly, accuracy, duration, etc.