Bell should return someone good, meaning a good prospect. Cruz might tempt a team that thinks he has one more stretch run, but he seems like the sort of old-timer who returns the next Jordy Barly. None of the others mentioned above seem likely to get anyone better than a couple of Fredericksburg or Wilmington bench players. C Hernandez will be a backup 2B for some team, meaning not worth much. Maybe Yadiel, but most teams already have a DH or two or three.
It seems like relief pitching matters more and more in MLB, so maybe the Nats can trade Rainey and Edwards. The others are too shaky for the Nats, so I can't imagine that a really good team will want them.
For us, the team will be hard to watch after Bell is gone. There will be Soto, Ruiz, and nobody.
Of the bad teams I have seen, I'd pick the 1957 Nats over this one. They went 55 - 99.