It will impact your life more than any amount of rent you can collect.

Question 5: At what point do I need to collect the proof of funds, earnest money deposit and purchase contract from the end buyer?

If the properties are split into more than one LLC, then each LLC will need its own accounts.Checking: collect all income here, then use it to pay bills.

Here is the answer that i got:"We collect predominately listing (asking) rents although we do have some actual rental data in the system. 

Execute the plan, build the units, get the long term financing that covers the extra builds, collect more rent and lastly, increase your net worth substantially. 

You could use some of the rent collected in the duplex to increase your income basis.

Your property manager is the only one that will tell you the truth, “No I won’t manage that property” and have to put their money where their month is when it comes to how much money you can collect for rent, clientele, area, etc.This is an ongoing relationship, and a good manager can refer you to other contacts.Ask for referrals.

Other people like in BP just want to collect rent and do FIRE when they're 31 LOLif not because of high tech military industry including aerospace/naval industry, high tech industry and dominating US dollar, USA almost has no competitive edge anymore in the world except these three things....

I am unaware of any state that does not allow you to collect advanced rent, but I am not an expert in all states. 

A handful will allow it as long as you are not collecting significant additional income from it.