Looking back, he sucked me in by "being a nice guy", but really he appealed to my ego. 

However, two Appeals Court decisions say you can allocate mortgage interest and property taxes differently, by treating actual rental occupancy days as rental days and all other days — including days of vacancy — as personal days.Before the TCJA, the Appeals Court method was often more beneficial because (1) it allocates more mortgage interest and property taxes to Schedule A (where you could usually fully write off these expenses as allowable itemized deductions under prior law) and (2) it allocates less mortgage interest and property taxes to Schedule E, which usually allowed you to currently deduct more of the other expenses allocable to rental usage (property insurance, utilities, etc.) on Schedule E when applying the rental income limitation.But after the TCJA changes, some vacation-home owners may benefit from using the IRS-approved method instead of the Appeals Court method.

Are there any other updates that my wife and I should do to increase the value of the house and increase the appeal for future renters?

This is looking more and more like a difference in culture and mindset than one based on anything else.I think that while it's true that granite will certainly allow any rental to rent more easily, the price differential in my area in countertop materials is about $300 for 32 square feet of the materials and tools you need to build laminate countertops by yourself or have a handyman build them at $50-$75/hr, and $1300 cheapest minimum possible for finished and installed counters, with that $1K typically climbing to almost $3K when all's said and done, because there's very little difference in the visual quality of the cheapest granite from laminate and people who buy granite for rentals are habitually looking for something that's "nice," that "pops."

If, though, the county's values are too high for your properties (IE more than you paid) - you can still challenge by filing an appeal with the Board of Equalization by July 8.Appeal form is on their website - search Jackson County Board of Equalization.Ron

Apparently why gambling appealed to me - instant gratification?

How's that for a visual?

There are many reasons for it, like your price is not competitive, there are many alike properties in your area etc. what you need to do is to take more appealing photos to attract more potential tenants.

Millennials, who coliving appeals to,  like to live in city centers.

You definitely have skills that another interested investor could find appealing and therefore partnering up is a possibility to look into.