This is not intended to be a discussion about the options for investment, rather how to conduct real estate settlements in non fiat currency.It is (or should be) evident by now that the status of the USD as the world's reserve currency (or at least our exorbitant privilege) will continue to be marginalized in the coming years (and decades) and that investors are factoring in elevated risks of currency inflation and debasement into and onto their portfolios. 

I have signed a lease and transferred payment of 1st month's rent and security deposit to the landlord.

Should I break that into 12 month payments and add to his existing monthly payment?

Make sure your financial situation is stable, with a strong down payment, an excellent credit score, and a clear grasp of your budget and objectives.

Ask to see a copy of the lease and look for the length of lease, current rent amount, tenant obligations like paying for utilities and adhering to house rules and look for Landlord obligations like things the landlord may currently being paying for (like trash and water)Make sure to have an assignment of the lease and clear language on the security deposit WITH interest shall be transferred to the new owner at settlement.Consider tenant quality - what’s their payment history looked like, obtain rent receipts or bank statements from the seller to review on-time payment history.

In my models, I have expenses (less mortgage payments) track the same number so I find the total rate of return to be relatively insensitive to this number.

I could pretty comfortably afford my monthly out of pocket payment due to income and help from my partner. 

His monthly payment is $1365/mo, and the house is 3 years old. 

Once we determine the rental value, we aim for a monthly payment to the seller at approximately 50% of the market rate.

This means that they are going to look at the ratio of the Net Operating Income (NOI, or income - expenses) divided by the monthly debt service (your monthly payment).