Ideally, we'd like to acquire one or two duplexes that meet the 1% rule and provide us with $1,000–$2,000 USD per month after property management fees and other expenses.

More than likely the asset will in a location where cap ex & management/operational costs are disproportionately higher and therefore your expense ratio will also have to be adjusted to a higher number.  

One thing I can assure you, there isn't an asset class in the world that would have me comfortable at 100% leverage.Your money on the sidelines is great in principal but in reality it will be put to work covering the net loss on the properties you buy as you will be overleveraged and won't be able to cover your operating expenses with the rent.

Be mindful of short-term capital gains tax, as profits from flips held for less than a year are taxed as ordinary income, and frequent flipping may result in self-employment taxes.While profits from flips do not qualify for 1031 exchanges (since flips are considered inventory, not investment properties), you can minimize your tax burden by deducting allowable expenses like renovation costs, loan interest, and holding expenses.If you're considering diversifying into rentals, explore opportunities to benefit from long-term tax advantages such as depreciation and lower long-term capital gains rates.

"Fall in love with people, not with houses".Did your agent do a "cash out analysis" to show how much winds up in your pocket after the sale expenses?

The way I can imagine is perhaps putting up additional cinder blocks but that sounds expensive.

Then determine your burn rate, days between call to cash, take down ability and average profit per opportunity. 

The advice is downright bad; not applicable to the average Billy & Barbara, some signs of bragging among other concerns.

While I do take into consideration all the relevant expenses when I vet a property I still like to see at least $200/door cash flow so I can more easily build up my reserves and have some money to work with.  

Each potential buyer has come to their own conclusion that it would be too much hassle and risk to manage in this fashion vs a traditional rental even though the average cap rate in our area has been half that at best.