It's a great way to get brought up to speed with the city's rules and regulations as well as get you connected with their hotlines/ other resources for further questions.

Then you can go into the zoning code and find out what the requirements are for setbacks and  various other rules. 

Link to article: https://bit.ly/2ZEAVPdLink to rule updates: https://www.irs.gov/pub/irs-drop/reg-120186-18-nprm.pdf

You may think the purpose does not matter but it can as there are different zoning and different rules for different areas.

The mythical $100000 house with $1000 per month rent. 50% rule leaves $500 cash per month on the paid off house.

The rules vary so much from state to state.how can I find out if there’s an existing mortgage?

If you lease option where the payments or part of the payments go to the purchase of the house, you also need a licence.If you lease option, where there is a fair market value payoff at the end of the term, and you are not going to carry paper you do not need a licence.Also- if you are selling the home on a purchase contract (could be rent to own or a lease option depending on how it is written), you might (probably) fall under the rules of replevin (repossession) and not eviction. 

If you have to explain the business model to the guy then that should be a red flag he doesn’t want you as a customer .one of the main rules of investing is to seek competent advise .

I've heard everyting from 2-3% all the way up to 10% of gross rents as a rule of thumb. 

Just be sure you follow the rules if you use the 21st financing, or they might call the notes due and you will need to find other funding for the homes.If you pull in the homes with your own cash, then resell them using the regular funding, 21st or Triad.