Is there anything I should focus on for the design / layout if the purpose is mainly for renting out? 

Consider starting small by house hacking a single-family home, renting out rooms, or adding an ADU if possible.

Weekend work is emergency only and it gets billed out at double our rate . 

When I search for rentals as a user and not as a landlord the search result shows as apartments with 3 units and when I click it then it brings up all 3 houses and says which unit the user want to go to.I paid for this premium listing and want my listing to be separated out.

Second thing would be to work with a contractor, this is great stuff to do since you know building a house, building material costs, and knowledge of right and wrong what to do. 

Any tips or insights would be greatly appreciated!

It takes enough of your margin, which you don't have because you put so little down in this market.

You will want to check your laws first, it is illegal in FL to require renters insurance.

Truthfully horrified that this is an individual who wants to raise capital from others "to scale" after owning section 8 rentals for 2 years.

Hope this help.