The drafter will tell you what the expected timeline for design will be, timing for permits with city, what the lot and zoning allow you to do… etc The contractor : has to be someone that knows how to do the work (experience), is not too expensive so that the investment makes sense at the end, but is also not unrealistically cheap, to the point that they won't finish the project or they will simply run off with your money… Assuming you have an honest and experienced well priced contractor, then they will give you an understanding of costs for the entire project (a ball park bc you won't know 100% until you get RTI permits from the city (approval)). 

20% down lowers the chance of default.

If you are limited to lower-priced homes than some of the higher-priced cities then that will help determine your start.

I bought it as a primary residence but it’s sitting empty majority of the time as I work in New Mexico 95% of the time and get per diem to be here which more than covers my New Mexico living expenses.

I have no idea what the cost would be for some sort of them spraying stuff all over the place, but it might be a small expense compared to losing a valuable tenant.

It will be much harder and more expensive to finance anything over a 4 units and 5% down won’t be an option. 

Vacancy is getting expensive on my other rentals so I figured they could manage their own turnovers.

I use Stessa to keep track of all expenses and comes handy for taxes.

Or that they are way more expensive than their competitors. 

I would agree and recommend to FHA into a duplex, rent out one side to substantially lower living costs, generate equity, and build cash flow.I’d recommend listening to Biggerpockets podcasts, there’s also a great selection of books available that help break down each aspect of Real Estate investing.Then honestly, just look and study the area that you are interested in starting out in to get a feel for everything and think about each property you see.