This is not all consuming during Due Diligence- but there will be time required to manage the process and consultants.Ok, once you have the property and team in place to oversee- in most cases a professional property manager will minimize the time required on your part.  

Main concern is in terms of liability and time consuming being both.  

Keep in mind that in this case you would be originating a loan for an owner occupant, which means that you must be mindful of Dodd Frank consumer lending requirements and compliance. 

What are your monthly payments on your consumer debt?

Due diligence is "scary" and time-consuming, I've seen people ask "how to do due diligence" so I thought I would share “my method” after 12+ years as a consultant.I'll like to start by giving you my thoughts on what due diligence is and the true role it plays.First, the obvious one, due diligence is necessary so you DO NOT LOSE YOUR INVESTMENT BY BUYING THE "WRONG" MORTGAGE.

Private lenders/investors can't afford to comply with the consumer protection rules in Dodd-Frank.

Check the Department of Consumer Affairs for both; they have links and have a detailed page outlining exactly what you need in addition to the fee's you will need to pay.Nassau makes it extremely difficult; you must be able to validate past experience and they question EVERYTHING.Suffolk is easier; fill out information, take a test and that's it.NYC same as above.

For example, a mid-range estimate for per loan Dodd-Frank/CFPB compliance costs is $5,000 that consumers must pay one way or another, but let's say lenders already bake $4,000 of that into the rate by default (loan will sell for $4k more with a higher rate, as part of a mortgage backed security on Wall Street), leaving you with a $1000 "underwriting fee" to pay. $1,000 is 1% of a $100k loan, but only 0.2% of a $500k loan.

I am following that model but find myself consumed by excel and formulas.

Consume it.