If a character finds himself in a ship that

-he doesnt own and isnt on the crewlist,
-and the ship is also docked in another one that is also not owned by the character and no crewlist access

1. can he still step into the docking bay?

2. What if the same ship with the character is not docked, but floating in space and there is another ship at that exact location, the character having crewlist access to it?

#1 No. Without Crewlist/Pilot/Commander, you may not board a ship/vehicle/facility/station/etc. The Crewlist status of the ship a PC is aboard doesn't matter, the Crewlist/Pilot/Commander/Owner status of the destination is what matters.

#2 Definitely: If you have crewlist on an entity, you may board it as long as there is room to board.