Its possible that the starspeeders are set open to all to allow their passengers to get onboard initially. The don't necessarily stay above planets, but they should move I think. Not sure quite how they are programmed to move.
As for your keycards, most likely they will be destroyed. Can you give an ID number of one of them so I could take a look?
From what I've seen so far, Starspeeders don't continue travel automatically after arriving at their temporary destination (i.e. after ascending/descending, sublight travel or hyperspace travel). During that waiting time, you should therefore be able to enter the ship if you are nearby. Maybe that's something that should be changed?