I'm not going to speculate on how to fix the Raps during this season, but assuming nothing major changes before the end of the season, here's what I'd start doing after the last game of the regular season:
1. Let BC go, replace him with Stefanski in the interim, perhaps permanently.
2. Fire Casey (or demote him to Defensive Assistant Coach) and the assistant coaches, and hire one of SVG, JVG, D'Antoni, Mike Brown, Nate McMillan or Brian Shaw. If it is at all possible, hire more than one as an assistant to whoever is HC.
3. Sign Jose to a much, much more reasonable contract
(I don't see him getting traded, pretty much ever).
4. Trade some combination of Ross, Ed, Amir and Jose for any player who is a quality starter on a championship team (preferably not a PG), or a starter and and the sixth man of playoff team.
5. Throw the max at Josh Smith and Al Jefferson (or something a little below the max for Paul Millsap). Also see if Stephen Jackson can be had without paying an arm and a leg.
6. Get Magloire to sit on the bench next year, whether or not he's officially a coach.
7. See if any international stars are worth giving small contracts to, because they have to be better than McGuire and Lucas, and probably Anderson and Gray too.
8. If none of these roster changes come together, trade Bargnani, Lowry, Jose and DeRozan for as many lottery picks/high ceiling lottery rookies/sophomores as possible. Put out a line-up of Rookie/Ross/Fields/Davis/Valanciunas. Maybe generate some interest by getting AI to play point.
9. Tanks for three years with what would be a bottom 5 team. Draft the BPA every time and make draft day trades if there's a positional jam. Add one more mediocre year to see how the newest rookies pan-out. Trade the next first-rounder and any rookies who haven't fully panned out for someone near all-star calibre at whatever position is still lacking. Take on whatever all-star calibre player has the worst contract.
= playoffs for 3-5 years, 1 ECF appearance
Lather, rinse, repeat.