You can take my game… when you pry my cold, dead fingers off the board!
We play it free move and free of charge. Both ways
We played it this way too, rationale being that using the secret passage doesn't normally take "1" movement space, it replaces your entire move. So who's to say if it should add 1 or 2 or 3 spaces when you use it? That was our reasoning for taking the "free move" liberally to mean no added spaces.
(To comment on the other point, I don't remember if we felt she was underpowered or not.)