A: As long as the vent you are trying to cover is the same size this product will meet your needs.
A: Yes. However, you need to remove the check-valve type flap before installing.
A: The cap on the vent prevents water from coming in to the membrane of the roof. The amount of sealing is up to the installer.
A: No. It has a check flap.
A: No ,if properly installed and sealed. The vent itself has a damper to prevent weather and rodents from entering as well as bird wire.
A: Depending on the size of the duct, you may use either a male duct that is crimped or a female duct with a collar.
A: The rigid duct that connects to the vent hood is the female end. You then wrap it with aluminum duct tape made for heating and air ducts. You could run a couple of 1/2" self-tapping screws into it before wrapping if the metal (rigid) duct is heavy.