Max dti for automated approval through GUS is 47% housing ratio and a 57% back end ratio (and this is pretty much everyone, lenders don't manually underwrite unless there is an automated approval issue) - even then 31% and 43% are just placeholders, HUD allows 37% and 47% by meeting residual income requirements and no further compensating factors on R/E loans, and you can exceed 37% and 47% (most lenders will cap back end at 50%, but you can go to 57%) with strong compensating factors, such as assets.  

Well, all the costs to run a property is something you factor in before you even make an offer on the property.

Some criteria you should have a clear cut answer or might be as follows.Income to Rent Ratio - (Monthly Gross Income = 3xMonthly Rent)Credit Score - (600 or 650 or something like this)Credit History - no late payments within X number of monthsOther Debt - factor other debt into the above Income/Rent RatioReferences - how many and from who, and then contact them.To answer your question directly, I probably would not rent to this person.

There may be other factors that come into play, but that's the high level view.

How is the Interest Rate factored into this type of loan ......

So many questions.Is it manufacturing suits, office space, retail, etc.There are many factors but mostly you look at sustainability.How long are the leases, would you be able to cover all expenses and pay yourself?

I can throw out some general numbers for you, knowing that it will depend on a variety of factors for your individual situation.

I live in the Hartford area of CT and up until learning about the BRRRR strategy on BP, have really only been focused on an owner occupied Multifamily (3 or 4 units) as I was pre-approved for 5% down up to 275k (more when 75% of property income factored).

You need to factor for property management.The goal is good, just make sure the math works.

I can tell that you are a numbers guy.I would encourage you to spend a few minutes with every deal working on your gut-check factor.