He bought it when  the location was a D neighborhood but now its a solid C or C+ with a very promising future as it is located within 3/4 mile of the streetcar extension line.

My thoughts was if need be ask for extension on closing, put our 25% down payment, and when refi is done, turn around and use HELOC again to cover portion we were going to finance.

Please note that you are obligated to pay back their 401k (regardless of the performance of your real estate investment).Per the loan offset rules that went into effect with the 2018 Tax and Job Act: if you leave your job and the loan is current at the time you leave your job but then the loan goes into default because you left your job, you will have until your tax return deadline (including any timely filed extension) to make the loan current by depositing the outstanding balance into an IRA (and thereby avoid the taxes and penalties that would otherwise apply).If you are self-employed with no full-time employees & you can rollover the funds, you could set up a Solo 401k, rollover the funds and take a 401k loan from the Solo 401k.

With the extensive fair housing laws these days, I feel it's important to advertise your criteria and I do that by sending out a tenant profile to every inquiry before I go any further in the process.

The calculators are great and I have been using them extensively in analyzing deals. 

You need to talk to (a few) tax attorneys or accountants who work with international investors.We work extensively with overseas real estate investors.

We're not quite in the 11th hour yet but it's close.You might have more options filing an extension and interviewing CPAs in May or June for a summer engagement.

I definitely will do extensive research before jumping into annuities - index funds feel like a better move for my life stage but I’m still digging.Per your advice, I’ve been stacking cash and looking for additional investment properties but honestly haven’t found any deals that pass my criteria in the last 1-2 years.

I prefer the idea of cash flow over extensive rehabilitation on a property.

Though, of course, know that all CPAs are likely very busy right now, so you may end up having to file an extension if no one can fit you in right now.