One more thing came to me this morning. When you rotate the light trap (which is also the bulk roll lid), it seems to stop just short of the fully closed position. You need to give it a little bit more of a turn to snap the light trap closed. Then the lever to open the film cassette side is free to move. I think the lever is being forced into the lid and opening up the gap you decribed because the lid needs to rotate a bit further.
As far as the light you leaked into the bulk roll, I would pull off 2 feet and throw it away, then load one roll and test it for light leak damage.