Given that Voyager was supposed to have some resource constraints (replicator rations perhaps being the most notable example), theft doesn't seem all that improbable amongst the morally compromised.Petty crimes are a possibility, but with little reason to steal it would have to be someone with kleptomania. That or other physical or mental issues are also unlikely because Chakotay is choosing these people to be members of his crew, so he's not going to pick anyone who is a liability.
I also think the Maquis may have been far more willing to embrace people who may have had physical or mental challenges than Starfleet. Chakotay didn't necessarily have the luxury of turning people down in hopes of getting the best of the best.