The issue I'm running into is that the client has a low credit score (below min FICO guidelines) and with her on the loan, they wouldn't qualify.

If there are any issues with the tenant or the property, you'll need to communicate with both the tenant and the PHA to resolve them.In my experience, Section 8 tenants can be some of the most reliable renters.

I paid the collateral mortgage through by using Wise, after paid, they said they require pay 25% instead of 20% because their management team cannot proof. they provided different wise account and I become suspicious but I still paid.They claimed they would disburse my loan, but due to a system issue, they could not.

Unless there is an issue within 30 days of the tenant moving in. 

We also have issues trying to get our ServiceTechs there for a bid as they may be caught up on other jobs that need to be completed first. 

You can have some issues but usually nothing huge.

Some areas of interest are: is the property going to be harder to sell, what kinds of issues should I anticipate, has anyone ever dealt with this before, etc etc.

There are estimated 8.5M Akiyas in Japan, completely vacant, including in major cities like Tokyo, Osaka, and Kyoto. https://www.businessinsider.com/japan-millions-empty-home-ak....

I spoke directly with Drew Sygit - the founder of LogicalPM and we spent a good portion of 60-90 minutes chatting about the current portfolio, the issues I've faced, and how his company plans to solve it. 

Are people driving or walking, if they have to street park high crime is a bigger issue.