Roommate issue

I am renting a 2-bedroom condo in Arizona on a lease with private owners. I am the only one on the lease and the landlords are 100% aware that my husband has a felony conviction on his record that dates back to 10 years ago. This being said, He is a prohibited possessor, he cannot have any firearms in the house. We are trying to rent out the 2nd bedroom in order to help with the cost of rent, which is 100% accepted by the landlords. We recently had a man agree to rent the room. I notified him that there was a non-refundable deposit, and the cost of the rent was negotiated, and it was understood that there would be a 2-week notice if he was going to move out. On the night he moved in, the roommate wrote me a check in the amount of parital rent + deposit. My husband asked if there were any firearms, to which the roommate responded there was. My husband told the roommate it needed to be removed from the home, and unaccessible to my husband. The next day, I took the check to the bank. I received a call later that the roommate had moved all of his belongings out and wanted his check back in exchange for the keys. I told him he would not get the amount of his deposit back as it was non-refundable. A few days later, the check cleared and I made a couple of purchases. A few days after that, the check was returned and I was charged $77 in fees for my purchases and the returned check. Here are my three questions:

1. Roommate said that it was illegal for me to not have notified him of my husband's criminal background and the inability to bring his weapon. However, as soon as we realized he had the weapon, we told him what needed to be done about it. Was it illegal of me to have not notified him upfront?

2. Is it likely that I would win a case against him in small claims court to get the deposit back as well as the fees associated with the purchases as a result of the returned check?

3. We did not have a "signed lease agreement", however, I have emails between the roommate and I showing the terms agreed to (ie. 2 week notice, cost of rent, cost of deposit). Is this valid in court as a signed agreement? Also I have a copy of the returned check, is this also considered a signed agreement?

Any and all help on this will be greatly appreciated. Thank you!!