I have no problem buying a no-title bike, provided that a) the title has no liens b) the VIN runs clean and c) I get a notarized BOS from the seller. Carry that BOS with you and you'll never have a problem.
There is legally only one way to make sure that ownership has been transfered. And that is the transfer of the titel. There is no greyzone. Especially not if a seller should experience sudden loss of memory.
ONe more thing to think about , not buying a bike with a Title salvage or otherwise. If you have issues beyond your ability and need to take the bike to a dealership, you may have issues with getting them to work on it. I was looking at a CBR600F4 with no VIN, the guy could not get it to run right. I said ok if you take it to a dealer then we are cool with that. He said "no dealer will touch the bike without a VIN" . Whether this is true or not I can't say, did not buy the bike. My ugglee Gixxer has a title , clean and clear. At the minimum I would only accept a Salvage title or Clear. No need to have the hassles ya know
My '07 ZX6R track/race bike isn't titled and neither was my '05 Gix 600 and i have never had any issues. I will purposely buy a bike out of state or from an individual so they don't automatically tack on the title and registration fees. I don't want to pay sales tax or any other fees on a bike that will never see a public road.