I would rather pay top dollar and let the GC take all the risk and have the attorneys keep them in check for timelines with contract documents.

It was our second property, and I am in contract for a third presently.  

You need to assign your lease option memorandum BEFORE the buyer/seller enter into a contract with each other. 

I want to purchase in America, I read that it's legal for Non-US residents to do it.

My background as a lawyer will help with the contract side of things.  

Not a legal advice, but AFAIK you cannot mix IRA funds and loans unless your IRA invests in a security and not in a property directly.

They allow the seller to sell the property to someone else(unencumbered) and at the same time give you equitable interest to legally market it, IF they didn’t want the encumbrance of a regular option.

It is in my opinion a necessity or you become a legal target.

I have thought about vacancies, updating costs, and maintenance costs along with legal and leasing costs.

I read a lot of books and threads regarding the importance of Due Dilligence for the apartment buildings.After the proptery is under contact,I will definitely do the detail due dilligence in person and with propterty manager or contractor.But still I have the concern that before I put the proptery under contract,if I am in long distance or out of state,how could I do the due dilligence to do the pre-acqucition analysis (repostition chance,how much value can de added)?