Absolutely do not execute a release prior to payment.  

I have self managed prior to this experience. 

I am finding it difficult comparing similar MFH properties to one another as there are multiple variables that do not match up completely.

What about the comparables?

If you take an application fee and you had a prior applicant pending and they qualified,, and they paid the deposit and signed everything,, then if you had a back up application waiting you'd return the funds to the applicant and not run the form.

I'm living in Tucson right now and it's a great place to invest especially if your just starting off since it's cheap compared to other parts of the country.

If comparable homes support the value, yes.

So that's cool :) Considering the situation with the sale and comparing the contract options, I would be comfortable doing a purchase agreement on this with some legal verification.

I can require positive prior landlord references, though.

However this is not something you worry about after you close    You need to have this figured out prior to closing.