The leads are horrible and I've heard that some agents have had success getting out based on the new lawsuit selling one lead to multiple agents.

Most mortgage originators sell their mortgages to Fanny/Freddy and so follow their guidelines. 

One property did at least provide reasons why they were selling the property (I had to ask, because the property's cash flow is insane based on their description). 

My digital marketing experience comes primarily from selling physical products such as t-shirts, wall art, family gifts, etc… on Facebook, Google, Etsy.

While you have depreciation owning real estate, less than 10% do a 1031 exchange so you end up paying those taxes when you sell so you just defer them - and for those investing $100k it’s not life changing money.There are many REIT’s and private funds that offer tax advantages as well.

At some point in the near future I will sell everything (small to medium properties in the $300K - $7M) and do a 1031 exchange (so I don't get slammed with taxes) into a handful of large income producing properties...hire a management company and call it a day.

We could do a "Live and Flip" and sell the properties after 2 years and use our equity for the next deal.

If I ran a boarding house or hotel as the op has tried to sell it, the place would be staffed.

Do I sell the duplex in order to afford a larger multifamily property?

Better yet and probably and easier sell.. is to have the seller wrap their own first and let them make some delta..