Yearly net cashflow after absolutely all costs and a margin of safety should be between $15,000 - $20,000.Lessons learned?

I have considered creating my own Property Management LLC to do the work above and hiring my dad as an employee, however, I was told this would provide no benefit in terms of liability and it would just add costs and more taxes.I would appreciate your feedback.

I think the reason why they suggest this is in order to avoid any potential lawsuits regarding Fair Housing Laws. 

A PM can cost you 10-15% per year but they can also keep you at market rate and protect you from losses.

With my down payment, closing costs, and renovations, I will have put down around 70k (down payment and renovations).

Partner Driven financed the Faith Home Rd deal using its own capital, covering the $22,000 purchase price and $30,000 in renovation costs.

if you own the land free and clear there are options for financing with no upfront cost with closing costs and initial draw coming from the land 

You're in for an uphill fight for SO many reasons. 4 projects and total of 500 units?

The reason for the lengthy time is he has given me the impression he relies on this income to sustain he and his wife.

Understand the fees involved and calculate the total cost for an entire year of management so you can compare the different managers.