If your living in a town and you see someones plot with a chest on it and that chest is not locked can people steal from it or is this not allowed? I'm pretty sure it's not allowed right?
It's allowed, but it is generally frowned upon by the users here\ (also this should be moved to help & support)
A town mayor can't create a town rule that contradicts a server rule. If they had a rule saying "You're not allowed to steal from unlocked chests" this won't be enforced by the staff team.
The worst that can happen is the town mayor could evict you if they have a rule in place that prohibits stealing from chests. This doesn't justify doing it though
If there's valuables inside and just avoiding to do the bad thing is not good enough for you, you could lock their chest (adding them as well!) and leave a message saying that you locked their chest only for their safety and that they are welcome to ask you to remove the lock when you're both online. In order to lock a chest adding a person at the same time, the command is just: Code: /cprivate <username> instead of just: Code: /cprivate (and of course don't take anything from that chest lol)