I would definitely trade Barbosa for another draft pick, especially if we aren't anywhere close
to the playoff hunt by the deadline.
I'd explore my options with Davis, but I'd only trade him for a piece that would significantly upgrade the team. Maybe see if any contending teams would be willing to give up a young piece for Jose.
EDIT: In fact, as much of a Bargnani
supporter I am, I'd also try to gauge the kind of trade value he'd have and what kind of haul he'd bring back. Maybe even shop DeRozan a little.
Fact is, nobody on this team is untradeable except V maybe.