Have your notified your insurance agent/company that you are no longer living in the property and that it's under renovation?

My first duplex was a turnkey, off market property.

If I got a home equity loan for Property 1 and used the proceeds as downpayment for Property 2 and then got a 2nd loan for the remaining 75% purchase price for Property 2, when I sell Property 2, can I use the Property 1 loan as part of the cost basis for computing Property 2 capital gains?

If you’re using a car for business, log your mileage or depreciate the car; whichever method is favorable to you.

For example, I mention that every adult must pay a $XX application fee, pass my credit/criminal background, make a combined income of 3x the rent, and whether or not the property accepts pets.

Your decision to lease this property for short periods is what makes this a short term rental property, not the property itself.

I have an opportunity to get into a property that doesn’t have any true equity, but the terms are really good.

If the only MFH options you're finding are in areas you're not comfortable with, it might be worth focusing on a duplex in a better neighborhood.Saving up for a larger property later is a valid approach too, but keep in mind that real estate tends to appreciate over time, and waiting might make it harder to enter the market later.

Having local family gave me a built-in support system, market familiarity, and the confidence to manage a property from a distance if needed.

I wholesale some properties, and others make sense to take down as rentals.