I do believe in diversification and own stocks, however the majority of my money is in real estate.

For a small investment (let's say $100k) the incremental cost of my CPA preparing another state return takes away any value I get by the geographic diversification. 

This diversification could offer stability in case one market takes a dip.Option #4) Waiting for deals that cash flow in Idaho makes sense, especially if you believe that the market might stabilize and present more favorable opportunities.

.- Limited diversification: Using all cash might restrict your ability to invest in multiple properties.Hard Money LoanPros:- Faster approval: Hard money lenders are typically more concerned with the property's value than the borrower's creditworthiness.- Flexible terms: Hard money lenders might offer shorter loan terms, allowing for quicker returns.- Access to financing with poor credit: Investors that have lower credit scores might still qualify for hard money loans.Cons:- High interest rates: Hard money loans often come with higher interest rates, 10-18%, and fees.- Short repayment terms: Repayment periods are usually short, which can lead to higher monthly payments.- Short-Term Nature: If your property isn't sold or refinanced within the loan term, the high interest can eat into your profits.FHA LoanPros:- Low down payment: FHA loans require as little as 3.5% down, making it easier to get into real estate investment.- Government backing: FHA loans are insured by the government, potentially making lenders more willing to approve loans.- Assumable loans: If you sell the property, the buyer might be able to assume your FHA loan.Cons:- Property standards: FHA loans require properties to meet certain standards, which might limit options for investment properties.- Mortgage insurance premium: You'll have to pay both an upfront and annual MIP, increasing your costs.- Residency requirements: FHA loans are meant for primary residences, so you can't use them for investment properties unless you are house hacking.Traditional MortgagesPros:- Equity building: You start building equity immediately with a larger down payment.- Lower Interest Rates: Traditional mortgages typically offer lower interest rates compared to other financing options.Long-Term Stability: Fixed-rate mortgages provide predictable monthly payments over the life of the loan, which can help with budgeting.- Property options: Traditional mortgages allow for a wide range of property types, including investment properties.Cons:- Higher credit score requirements: Traditional mortgages often require you to have a higher credit score.- Larger down payment: The 20% down payment can be a significant upfront cost.

You've got a good list and diversification at scale is a good key to any and every investment endeavor.   

The way we now deal with the FX risk this is diversification, I can be pretty relaxed about our Mongolian loses as it is a fraction of our investment pot. 

that does not seem like diversification :/Look up ian appolito on this site for great info on syndicators

On the plus side, having different income streams could help with diversification.

You appear to have a lot of your net worth in the NYC market.You are an agent so you likely know the market better than most which gives you an idea of how the future is.If you think the outlook is good, double down on your knowledge in the market on option 1.if you like diversification, go with option 2.

Diversification over various asset classes is key here .