1) Yes! While they will initially be re-imprisoned, a willingness to share information about those who have left will quickly earn them their freedom. For the sake of not tying up everyone's time, we'll say that all remaining guests (both welcomed and imprisoned) will be interrogated in a week or so. Those who cooperate will be rewarded. Everyone will continue to be watched heavily, though.

2) During interrogations, they would be able to speak to the apprentice mages but no one higher. Ambrose is a busy man and the royals don't take part in such things.

These options will be available when the posts for Solvunn and the Free Cities go up, in a third post for those who remain in Thorne and Nott.