Oddly, one comment we received repeatedly is that people don’t won’t to bid on it because they are convinced it will end up in a bidding war and go for above 600k.

You say agents involvement is critical but then mention some kind of referral fee or consulting.To give you an idea I get contacted frequently by people on commercial deals where they went to contract but now realize mid deal they need help.

Repeat 20 times.

She pays by credit card and I repeatedly don't receive the rent by the first, usually the 5th-8th.

Not only will you stand out, you'll receive a higher level of repeat guests!

A frequent potential issue is when you transfer ownership entities near to the time of sale.  

If you're looking for the often repeated "class 'C' property in a class 'A' area." then just walk away.

It's always good to have a reliable lawyer who knows real estate laws in the state you invest in as a contact, but you won't be constantly calling a lawyer every week.Accountants, in general, are even less frequent than lawyers.

Flat hides the most, but it also attracts dirt, so depending on how long it takes to sell the house, you may have hand prints everywhere that you will have to frequently touch up.

I still think nothing beats California appreciation - if you can house hack, add an ADU buying locally has an advantage (can check on the renovation in person frequently, which I did on my Bay Area SFH) but the Midwest is much easier to get into real estate investing with less money.