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.

I miss the thrill of converting a van, traveling in it and then selling it. 

A person can be selling a property with a NOI of $100k and ask $4m, the CAP rate will reflect that their expectations are too high (for an investor at least) and all the market factors, location, comps, fed rates, will put their expectations on a leash (or justify it). 

It appears logical not to sell the primary residence once it's fully paid off, considering the associated taxes and fees.

@Maryam Mostafa there's a lot of scammers here in Detroit selling OOS investors crappy S8 properties in Class D areas!

That's a starter home in 2024... you would have no issues selling.

Sell your house.  

The sellers were motivated to sell and I was able to negotiate a price reduction.

Are you planning on selling?