I've had many clients utilize the rent by room strategy to great success. 

Hi Rafael,You can start with a SFR or duplex if you'd like to avoid using a property manager, but if you really want to scale up you should be utilizing a property manager.

I also utilize subordination of the mortgage and substitution of collateral where appropriate to create the “enhanced” returns that I seek.  

Whenever I read investor posts about unit count goals and utilizing section 8 rentals as the vehicle to scale a portfolio it loosely translates to buying real estate without paying attention to the fundamentals in the markets where they invest.

Or just used $15k as a downpayment and then had to make a couple months of payments to make the property ready, pay for inspections and repairs, commissions, utilities, advertising, and then it sat empty for a month and you had to make another payment?

The lease termination fee needs to be paid at the time they request this, do not substitute the security deposit for this purpose.This will ensure compensation for time, money and effort needed for a tenant turnover, including advertising and showing costs, regular repairs, utilities during vacancy etc.

An investor-friendly lender will help you devise a plan for savings and debt paydown.I'd also begin looking into which areas you'd like to invest in as well as strategies to utilize (i.e. househacking). 

However, looking at some payment processing options like stripe it seems there is close to a 3 percent fee for utilizing the service.

The basics are I would rent a number of units from the syndication LLC, would be responsible for management and expenses (ie utilities), and then I would keep a portion of the profit (basically my upside for managing the mid term rental units) and the other portion of the profit would go to the syndication LLC which now gets over market rent.

Vacant lots can go for as little as $5000 - $7500 and are usually between other houses so you at least know utilities should be on or near your site.