The restroom is easily handled:
1. Use the handicapped stall - there is more room such that the gun on the belt isn't seen unless Larry Craig is next door.
2. Get a bag from the register. Stand up in the stall, put gun in bag - do whatever. Then stand up, get gun out of bag and reholster.
The best Odd CC challenge is getting lucky on the first date when your partner doesn't know you are carrying a gun but thought you were just glad to see them.