Pretty,  as others have stated here, the permitting process through the City of Cape Coral has been hindered by their ability to scale up their staff to handle the massive demands for all permitting including new construction but also anything else that requires a permit, home improvements, sea walls, alternative sea walls, pools and more.From your post, I can see that you are frustrated, and I believe some of that is due to not understanding the steps and processes of new construction, including what must be done prior to submitting permits.

These properties include different foreclosures and those that sell below their market value.

If your goal is to scale, I would suggest running your numbers with property management costs included from the start.Also, if you plan on adding more properties soon, I would avoid anything that needs too much renovation upfront.

Your question is one that most Chicago investors, including myself, have gone back and forth on many times. 

But even then, seller financing is rarely substantially better than another investment they could make (including trust deed lending, which will often be at a higher rate than seller financing)In my experience, the owners who find owner financing advantageous are at the ends of their careers and are not interested in looking for another investment (other than the usual retirement funding sorts.)

You have to include the cost of your time and the work, especially on a "scary house" is daunting indeed. 

Many of our clients, including myself, have done that.

There are many service companies that will manage seller finance notes including the payments, escrow accounts, and documentation. 

I primarily invest in buy and holds, but I do a little bit of everything including fix and flips, airbnb's, mid-term rentals, and wholesaling.

Be sure to include one of more exit strategies in your LLC documents.