I'd keep him as the 13th forward if we can not find a good trade.
Then figure out a trade to get Leivo into an NHL lineup (Leafs or otherwise), and deal Rychel as well or keep him as a 13th/14th forward.
Unfortunately, it seems like Soshnikov and Kapanen are going to be in the AHL next year, at least to start. Maybe a team is willing to pay something for Soshnikov, but unlikely. Not unless they want a good depth forward for their AHL team who can be ready to contribute half way through the year or at the start of next year (or they are really desperate for bottom 6 wingers with skill and speed).