So think of it as the total cost of borrowing money. 

Please don’t “invest” any money in a class/bootcamp you aren’t willing and able to afford just burning.

She'll pay me market rate rent, thus keeping that money in the family, and the condo will eventually transition into a more traditional rental property that will support my retirement and that my children will one day inherit. 

The concept is "continuity of investment," meaning you can roll your gains forward, but you can't take any money off the table while still fully deferring taxes.In your case, if you withdraw the original 50k down payment, it will be treated as boot, and you will have to pay taxes on that amount.

If you want to spend the money you can consider triple pane.

While I am a lender, I personally use hard money on all of my own investment projects.

Find a deal that will actually make money for a buyer and you'll build a decent list from the initial interest.

Don't take out a HELOC Jason, it's not worth the time it takes for the amount of money you need.

When I did my research for buying my properties in Costa Rica, I had one of the big STR management companies like Evolve analyze my potential profits and I used that info to raise money through bringing on partners to buy the properties. 

Generally, these courses and training/coaching/guru programs are not worth the money.