I’ve noticed that credit unions tend to have slightly better interest rates since they typically are not for profit whereas a normal bank or broker is.

Low closing costs, with minimal documentation and competitive rates.

This is quite significant if they don't reduce rate at all until 2025.

Primary residence is valued at $1.8m with 10 years and $400K left on a 1.875% 15 year fixed rate mortgage.

This would allow you to keep that low 1st position rate. 

It's our existing tenant who wants to stay at a great rate, and we want to rent to them at that great rate.  

By analyzing metrics like sales figures and listing effectiveness ratings AI driven tools such as Relitixs "switch risk rating" and "rookie potential rating" enable recruiters to prioritize their actions and uncover agents with potential.Furthermore AI is constantly evolving, with machine learning algorithms adjusting to market shifts and refining grading systems, for accuracy and relevance.

Interested in a property in which agent is saying lender is not approving any borrowers as the rate was obtained during the lower interest rate environment, so they’re declining everyone who’s trying?

Once you find a general market, you can narrow your search further by looking at crime rates, school rankings, etc. 

I expect to offer to keep the rental rate the same based on the market, but know when I was a renter there was always an option to go month-to-month for a higher price.