Unfortunately, Uncle Sam always wants his cut ;)

Hear your Buffett comment loud and clear and current administration is already making waves.Thinking out loud - cashing out the brokerage account seems like it should be an all or nothing move, to maximize the reward from going all in on RE for FI. 

Although I’m sure the bank made it clear that rents would have to go up quite a bit in order to meet the monthly mortgage obligation.

And you can do it with little cash, 5% down conventional is better than 3.5% FHA.House hacking also gives you a chance to cut your teeth in all major skills: analyzing deals, buying process, financing, working with contractors, advertising for rent, background checks, property management.

This ensures you can provide them with a clear and accurate scope of work.

When the smoke clears after a sale, everything falls to the buyer's responsibility.  

This would likely take coordination with a tenant at some point - (ie - plenty of notice to them that they must vacate in order for you to sell the property)Since your current home is free and clear -  you could do a cash out refi or take out a new mortgage on the new house to be able to buy your paren't house and pay off the mortgage.  

Cut expenses and work, no way around it.

I suspect the owner could sell the property to a third party free and clear of your lender's claim to the income stream. 

So back to square one Property is in her name free and clear.