Well, a Colonel is probably afforded much more thought than your average conscript, so I don't think we can take that as a standard.
Perhaps, but he was allowed to stay in Germany, so it's not out of the question. That, and he's still only a colonel.
It requires a bit of finesse, which might mean it's out of reach, but the Germans saw the mutiny take place before their very eyes. So, with a bit of chatting with their prisoners, they should have a very good idea of what's going on. So this is where they start making offers. Send delegations under flag of truce. In the hearing of some of the men, make offers. Surrender, come sit out the rest of the war in a dry POW camp, with three hots. It is probably advisable to have the POWs do gardening, to keep them busy and provide some of their own food. After the war, melt back into France if you like, or stay in Germany, or Germany will help them migrate to the place of their choice.