Long term security. 

That's not really a full story so it's hard to say, but generally, if you don't feel secure or confident in the person you hired, you shouldn't have hired them.

Its essentially in the longterm best interest of the property owner to ensure there is a non-compete clause in all leases; merely for the benefit of securing longterm relationships with the tenants.A diverse tenant mix can attract a wider audience and contribute to a more vibrant environment.

Nice user interface, simple to set up, free door lock automation.We migrated to OwnerRez because we wanted a direct booking site and security deposits. 

A smart seller will have note, deed of trust/mortgage/etc. prepared by a local real estate attorney (yes, he/she may work with/at the title company) and be sure the security instrument is properly recorded in the land records. 

Tell them if they don't, you will take it out of their security deposit and they will have to replenish their deposit.

Credit score can help you secure a great rate so make sure to get started on that if you aren't already.

Can I use her security deposit to cover these legal fees I've incurred due to her not moving out?

I can tell you that you won't secure a REFI term longer than the term that is left on your lease. 

Do nothing...the tenant isn't renting that area and has no right to dictate how you use it as long as it poses no security/safety risk to them.