If you have to send them to collections later, it won't matter do any good, because their credit is already so bad that another hit won't affect them.They missed 60% of their payments.

Also, how much does the borrower’s track record or experience influence your final choice, especially if they've had success with similar projects?

There is no good investments, or bad investments.You as an investor need to decide what investing strategy works for you, define your criteria, understand if your criteria is possible in the market you are looking in, understand the risks/rewards of your critera, and then execute the purchase.While some agents are heavily knowledgeable about investments, most have zero clue.

A realtor could be an option, but keep in mind that they may be influenced by their commission.

If their behavior gets bad enough, we will non-renew them at lease-end. 

A lot of the properties below $100k I saw looked like in locations that were in pretty bad shape.

This is a great place to learn.Is there a reason that you are trying to make something that doesn't fit to a bad market.  

Overtime, rents started lagging and annual repair costs become $1500-2000.There are a lot of bad tenants on section 8.  

This is neighborhoodscout stats- since 2000: 287.98% or 5.75% annually which is 10/10 nationally- for last 10 years: 125.30% or 8.46% annually which is 9/10 annuallynot bad but not that impressive until you factor in leverage.

The seller was able to walk away from a bad situation with some money in her pocket, we will be helping her move and relocate into an apartment.