I believe the "Trust..." quotes from Q are more of a trust these people to be the actors that they are and play their roles accordingly. You can trust a lion to eat you in the Savannah. You can trust a hyena to try to steal the lion's share. You can trust a rattlesnake in the grass to rattle and strike. You can trust a criminal to always play the criminal part, just like you can trust a DS rat to be... a DS rat.