Namely, that if a tenant (in this case accompanied by a whole family) ends up stop paying rent and I would be on the hook for both covering the mortgage and dealing with open ended legal costs and time.

Depending on the lender (bank or alt. lender) you have to look at origination fees....points, doc prep, interest rate, frequency draws are allowed/min. draw amount allowed per request, interest payments vs. interest reserve & whether interest reserve is capitalized to fully understand the true cash requirements.

@Jordyn Ohs Assuming your heloc is re-advanceable and the rate is higher than your mortgage, I would suggest you pay your HELOC down as quickly as possible with any cash flow from the properties.

Over time I have amassed a good quantity of houses with no mortgages.

However, between the much lower mortgage interest rate in Europe and a better tax treatment in the US, I'd choose the former.

So are you saying the Mortgage One deal would be the way to go? 

That is the best option if you are truly trying to help a family member.you cannot get control of the mortgage, you can do sub2 but you are not in control, the bank could call it due if they see the property transfers title.The other way is for you to buy it from them at market rate, then rent it back to them at market rate.

Rates are high, usually in the high 8s or low 9s, and you may pay 2-4 points on the loan. 

Other KPIs and considerations you should evaluate when talking to any lender who offered private placement of loans/notes are historic default rate, how quickly they can place your funds (do you get preference over their income funds, for example), average interest rate - borrower note rate and what is passed through to you, are loans serviced by a 3rd party servicer or in house.

If trump hadn’t won you’d be forced to sell this year, but hopes are high he will extend his lower tax rates.