He collected first/last/security payments prior to move in date and was never heard from again.

You'd need to show the income on your tax returns and/or have a lease and first month's rent/security deposit for the unit you were living in.

City Wide property mgt is who I deal with and honestly when I ask for real numbers and updates I get a lot of BS run around sales talk speech. 

This means securing at least two bookings (to get a stay of less than 7 days) and completing all setup tasks.

To answer the title of your post, selling fsbo can be a good idea if:- you have experience selling RE- you price the home to sell- you have systems in place to collect inquiries and facilitate showings i.e. call center/email/google forms for screening inquiries, showing agent, lockbox, security alarm, etc. - you have dozens of local agents who can market the property for you and bring you a buyer- you are listing in a desirable area with low-inventory - you are not in a rush to sell

I negotiated the FSBO and was able to even secure a commission.

After a month of renovations, I listed it on the market on November 19th and secured a tenant with a lease starting on December 10th.

Quick context: I placed a tenant in one of my units after thorough background checks and collected security deposit + first month's prorated rent via Baselane (bad move!).

A 3' wide continual walking space perhaps? 

May be expensive but they are dedicated to private lender law, securities law and creditors' rights.