So, we require a nonrefundable Retainer Fee for 90 days of our time to find a rental property.

A higher LTV generally requires a higher DSCR ratio such as 1.25 instead of 1.

It's definitely possible to get a loan as a foreigner but the rates will be high(er) and the downpayment required will be as well.

Do have an idea of your preferred acquisition price and how much rehab might be required? 

As for the "seasoning", some lenders will require the property to be "stabilized" (perhaps 80%-90%+ occupied, depending on the lender) for 3 months, 6 months, etc. before they'll do a cash out refi.

Quote from @Jordan Kaylor: What is a “seasoning requirement”?  

What you spent on the land/lots can go towards your down payment and, if you've owned the land for more than 6 months, you can use the value of the property toward the cash injection requirement.

I do it myself and takes 20 to 30 minutes a month (did it yesterday for Dec), with about 7 of those minutes for 1 property in Blount County, TN which requires the form to be manually filled out, write a check, address an envelope, scan doc and check for my records and walk it to my mailbox.

Multifamily properties do require more management overall and typically appeal to a smaller, investor-focused buyer pool.At my stage, I prefer small MFH over anything else because of the stronger cash flow, scalability, and the more forgiving capex compared to larger MFH, but the best option depends on your goals and strategy. 

There are some home loan options that require as little as 3.5% or even 0% down.