I'm installing my fireplace insert and have a liner (6inch flex pipe) and insert collar adapter. 2 questions.

1. The adapter slides into the top of the insert and butts up against a rod that runs the damper. Should I notch the collar just a bit to allow a free moving rod?

2. No where do I see anyone sealing the small gap between the insert collar adapter and the insert. I slip it in and there is an 1/8 inch or so gap around the outside. Should this be sealed? With what: insulated gasket rope, calk? Won't smoke escape here or will the draw of the chimney take care of that?

Thanks for your insight,

Rick