You could learn how to find deals for investors and whole sell them. 

I see that the area does sell these properties frequently and over the years have been increasing in value. 3 years ago, these properties (fully deeded) were going for around $25k, and now are selling for around $60-90k.

I have a house in Fort Worth Texas, that I am trying to sell, but it is not selling the way I would want it to (beautiful house in transitional neighborhood).

I personally know of people who chased the STR Shiny object, could make it work and had to sell at a loss.I think these people didn't do a great job of due diligence and were overly optimistic of what they could make.

I was unable to get any deals due to the nature of the divorce process but now that is over and I am ready to invest flip, sell, and also buy and retain for BRRR. 

You can have a lot of social security, rental income, interest, dividends, etcI am not to say your income will be higher when you retire or that tax rates will be much higher, I am just here to say the only difference is 10% and not 30%.To add on all of this - If you keep your assets in a retirement account, your distribution will be taxed at marginal tax rates(Currently tax rates are between 10% and 37% + state taxes)If you invest personally in your own name, you have the opportunity to escape tax on any appreciation if you have heirs that inherit the property.Even if you decide to sell the property, you are paying taxes at the preferred capital gains tax rate(Currently at 0%, 15% or 20% + State taxes + Potentially NIIT)That difference alone pays for the 10% penalty.

What can I do to find more small multifamily properties or will more properties become available as rates drop and more people are looking to sell their properties?

They won’t sell because it’s spring and the vegetation will grow back this month anyways.  

For estate planning purposes, we want to change the title to a revocable trust where my husband and I are the trustees. will this have a negative tax implication for 1031 purposes if we want to sell these and purchase properties prior to my husband's passing?

The more they sell, the better that split gets.