(I bought it 3 years ago)I'm trying to see how long in the future I will need to do another gut renovation, so I can start saving up some money toward it.Things are in pretty good shape.

Would the best bet be for me to just park a chunk of that money in a high yield savings account until tax time?

This application automates "back of the envelope" calculations, making it easier and faster for users to find and assess profitable real estate opportunities based on their specific investment criteria.

Not just a real estate investment, but an investment into my marriage.

Early on (1978) I joined a couple of newly minted Real Estate Investor Association groups.  

I did a bit of research and wondering if the current interest rates, high real estate prices, and weak 12-14 week rental period make it a bad investment.

When the money dries up, they'll abandon your property and leave you with a bill.If your property is capable of producing a greater return as a corporate rental or short-term rental, I recommend you educate yourself on how to do that and then do it yourself.

Spent too much money on updates for a rental property.

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

You need to make sure that how the money is collected is 100% collected prior to them putting a single door in the door.