I don't think there's a forum for gameplay, yet, but we did make a few videos to show how we play:
https://www.youtube.com/watch?v=v1z3TXRMfvI&ab_channel=BobbyTwoHands
In general, you're not supposed to be 100% undetected. Your agents don't need to survive forever, just long enough to accomplish their objectives. Your enthralled noble might be valuable, but agents can be replaced when they get discovered and killed. You're playing as the evil side here, compassion isn't something you should be worrying about. If a vampire dies, just get another and continue the Great Plan.