I would take out the 401K loan towards the downpayment.If you sell stock, you have to pay taxes - You mentioned the 15% federal capital gains tax rate(if you are not in the top bracket, otherwise its 20%).You may also be subject to the 3.8  Net Investment Income Tax. 

If they just needed one more month, they might extend and pay the premium.I mention that, because if you are OK with the resident and just want them to sign a lease, tell them the MtM price will go up effective September 1, and is $400 more per month. 

Using the next ten years and the snowball method to pay them off.

I'd suggest trying to finding someone here with nothing to sell or through local networks that will give you some free advice before paying for a course.

She had to pay rent in May because she wasn't sure when her closing would take place.Landlord appears to have rented it out now.

@Hamada Beeka, since they have said they won't allow you to move in I would ask that they are offering to pay you.

Pay cash for the property and the rehab, then do cash out refi. 

I need to pay some good advisors for a few consults.

STR's are uncertain due to the term length, one month you can make all the money in the world, and the next you could be paying for those bills out of pocket, so it would have to be strategically operated, but at the same time they can be a fantastic source of income!

However, if we pay in cash, they will offer a 7% discount.