What happens when he gets into disputes with people and it turns violent?

My question, is there anything i can do to safeguard myself from any future legal disputes with this crazy tenant?

I am in the Courthouse almost every day of the week on issues related to; Bankruptcy, Medicaid, Elder Abuse, Family Law, Collections, Contract Disputes, and Landlord/Tenant disputes.

Here in Florida I have never seen it turn out favorably for a landlord to dispute this.  

Fully legitimate and no grounds to dispute.

We collected over 20 applications at the open house.We ended up having to serve another tenant a 60-day notice after several domestic disputes where the police (and in one case fire department) were called.

Next time I would charge them a pet fee instead of a deposit, if their dog destroys something you'll have to go through the deposit claim process which they could (and often do) dispute.  

It just means had you stayed, you could have disputed the $75 - not completely avoid paying a whole months rent. 

Vets can, of course, go through the process of disputing these reductions but many feel this is a hopeless venture.Gail

If there is ever a dispute with the owner I would think that is important so that you can attach their asset (property) in case you need to collect against them.