Can the Legionnaire also be used against ships that do not have an airlock, such as the Crusader Hercules? Are turret hardpoints alternative dockable breakthrough points?

At this point in time, we are only committing to it being able to breach dedicated airlock entry points, both the small and large varieties. While we would like manned turrets to be valid breach points in the future via EVA, it is not currently planned to allow automated docking systems to dock with them.