Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

I wrote an article that I think you'd find value in that will provide some answers to your question: https://www.straightupchicagoinvestor.com/blog/6-must-knows

Be willing to help others, listen to them, and provide value anytime you can and you will go far!

Paying off the mortgage can provide peace of mind and simplify retirement, while keeping the debt allows you to leverage your funds for higher returns through investments.

.• Retirement communities• Syndicates (from initial explorations, little transparency from providers, little oversight - almost leap of faith and trust in provider?)

Mortgage recasting is a great option for homeowners who:Have received a windfall, such as a bonus, inheritance, or proceeds from selling another property.Want to lower their monthly payments without extending their loan term or going through the hassle of refinancing.Are satisfied with their current interest rate and loan terms.How to Get StartedIf you’re considering mortgage recasting, here are the steps to take:Contact Your Lender: Ask if they offer mortgage recasting and confirm your loan’s eligibility.Determine the Lump Sum Amount: Decide how much you can afford to put toward your principal.Calculate Potential Savings: Use an online mortgage calculator or consult with your lender to estimate your new monthly payment and total savings.Submit the Request: Once you’ve made the lump sum payment, your lender will process the recasting and provide a new payment schedule.Final ThoughtsMortgage recasting can be a powerful tool for homeowners looking to reduce their monthly payments and save on interest without the cost and complexity of refinancing.

Now me, my agent, and the sellers agent have been trying to get in contact with the previous owner to receive these funds.

From investor friendly agents, lenders, escrow companies, anyone for a new wholesaler and soon investor. 

I heard that PropStream updates this data on a weekly to monthly basis, whereas PropertyRadar updates the data daily, providing fresher leads.

I would find out who the manufacturer is and send it to them and confirm they will provide a warranty on this.