I paid for a lifetime membership and then still got charged. 

They often think they're the smartest people in the room and, as such, they should be in charge. 

I am working with a RE-focused CPA this year who charges a flat fee of $2,500 and is very responsive so far.

It may sound nice to pay a 6% management fee but the extra fees can add up to be more than the other company that charges 10% with no additional fees.

In my market every PM would charge more than your projected $350/month (which I already indicated is not reality) to manage two average size units in a duplex.This does not mean cash flow does not exist. 

Furthermore, whole note investments benefit from an additional 0.5% annualized yield and are entitled to a share of any extension fees charged to the borrower."  

I did get lot rate for a similar rural park that is about 40 miles away, and they charge $350 per month, which is decent. 

With the transfer tax - you're being charged 2% of the property value (not the loan amount)!

The first few times, I didn't charge a late fee.

And not knowing their numbers also makes it next to impossible to know if you have a bad PM that's eating into your cash flow as well (Like Vacasa charging $800-1000 a month for elecrtic on a 4/3, 2000sqft house with a pool).