We had to submit proof that it was listed on MLS, so that's a non-negotiable.

Only real potential unknown for me is investing in a non-elevator building and unit is on 3rd floor.

There are many ways that the IRS has deemed appropriate to allocate tax basis between building(depreciable) and land(non-depreciable).One method is that you may want to see the ratio of land/building allocations of recent homes sold in your area.

A finance contingency, and Earnest Money Down non-refundable after DD is completed are typical.  

Do I fill out and sign the Seller Non-Agency Agreement or the Buyer Non-Agency Agreement even though the Real Estate Purchase Agreement does not have me listed as a broker?

I have seen some turnkey providers deal analysis sheets and noticed that some do have some questionable assumptions built in (very low/non existent vacancy and maintenance assumptions).

If they stated it worked, you should have requested/required proof of the working and non damaged door prior to closing (can be inspected any time before you closed).

Even non owner occupied SFR.

The property values range between $250k-$320k.Most of our tenants in the LTO program are families that were hit by the recession and haven't bounced back financially in terms of qualifying for a non-conventional loan.  

Are DST properties usually priced 10 - 15% higher than comparable Non 1031 properties ?