It really won't make a difference regarding renter demand and if you allow storage the tenants will just fill it up with crap and leave it for you to dispose of after they move out.An additional bonus is that since you're in AZ it is more square footage that does not need to be climate controlled.

Lisa, part of attacking your debt is creating disposable income to pay it off.

I can only answer the question for myself, but with 200K at my disposal, I'm mainly interested in making that money grow at an insane rate without too much active management. 

Have you thought about getting rid of the disposal and possibly the dishwasher?

Normal tenant issues: slow toilet, broken garbage disposal, broken electrical outlet, tile repair, etc. 

Over 5 years would be $393/month.So basically my concern is that for those first 4 to 5 years, I would be redirecting all my cash flow plus some disposable income in order to repay my dad.

Garbage Disposal for instance would go unfixed.

It authorizes me to change the locks and immediately dispose of any personal property left in the unit.

If the tenant has informed the landlord in writing that the belongings are abandoned, then the landlord can dispose of the items immediately without any liability to the tenant.

Make sure that you are getting insurance that is self storage specific that covers you for sale and disposal liability.