...124 to run fleeing from the mountain. ...125 to use a rope to climb the cliff. ...126 to quickly cast "summon stairs." ...127 to dodge under the falling rocks.
Re: Drawing Tiles/Movement
1) Yes, that is correct. Whether moving to a new space or an old space, it takes the same amount of air.
2) Neither. This has happened to me as well. The game only ends when you run out of air, not out of places to go - even if that does make finding your ship difficult. And you don't keep drawing tiles until you get something that would continue the path.
There are a number of Event Cards which remove all the tiles around you, or some of the tiles. I usually keep moving back and forth between the various dead ends (which yes, does use air) until a storm blows up and causes a new path to open up.