IMHO, I believe the bike is a non issue. I've never said this before, but the thought of a grown man using a bike as a get-away vehicle just seems silly to me. I believe he was just done, couldn't afford the lifestyle on his salary, probably overwhelmed with bills. Drove to work to tie up some loose ends, tossed his phone which was picked up by someone who happened to live on LI hence the ping. I think he left from Brooklyn. I don't think he ever came back to LI. No sightings, no interviews or folks coming forward to say they saw him, even scrap metal yard is an unconfirmed sighting.
NCNY's mention of someone RM was caught texting with, to me, is the #1 clue that he was keeping things from IM. I don't believe the happy picture IM is painting of their life. I just really believe he left.