Paying her (or locking in that you will cover 1st month's rent) before you've changed the locks could put you in a tight spot if she doesn't leave.

Squatter crawls through the attic to hook up to my new tenants' branch line. 

I don't see where any rainwater is coming in, but I am going to crawl in there after the next rain to verify. 

And if for reason you don't have enough equity to refi and pay it off, or something negatively happens with rates, then you could be in a tight spot. 

Start by finding an investor-friendly real estate agent who understands the process and can spot deals.

You're in a tough spot, but here’s what you can do:IRS Payment Plan: Set up a payment plan with the IRS to spread out the $200K tax bill.

Being proactive can help you spot potential red flags and make a more informed decision about your purchase.

If targeting new construction, keep searching for an extended period of time until you find a builder that has a good deal, avoid builders that clearly will be difficult to work with, it was easy to spot.

I personally think you're in a great spot because you are asking questions and not just throwing your money around. 

A few spots will do it, but the property needs to have a DSCR of at least 1.25 or better and 720-740+ fico at that LTV.