The Reds should be looking to trade Alonso and Valaika. I think both of these guys are hopelessly blocked at the major league level. If Phillips leaves next year, which I doubt, the Reds will look for a veteran rather than using Valaika as a starter IMO.
I would consider trading Cozart or Janish if the Reds deal for a big time shortstop, say Reyes of the Mets. Otherwise, I would hold onto both.
I wouldn't trade Sappelt. I wouldn't trade Mesoraco. I wouldn't trade Heisey. I wouldn't trade Francisco. I wouldn't trade Frazier. I think they all fit the Reds needs for the next few years. Grandal was just drafted, wouldn't deal him even if possible.
I would trade Lecure and Maloney as part of a deal for pitching. Otherwise, I would keep them.
The Reds depth is probably the best part of the organization. I wouldn't trade good prospects - except when they are major league ready and blocked. I would also trade guys for better players in a one-sided deal, obviously.