Nobody has a perfect crystal ball, but probably next year it MIGHT be 4% (or even still higher). 

It’s the same temperature right now in MN as is it is Vegas.

Ball park numbers: how much does it cost to fully replace a water heater with labor?

It’s a little bit of a different ball game than resale properties.

While using a glue with a floating floor will help with separation issues in variable temperature.

If the heat isn't above the legally required temperature they might declare the unit uninhabitable and boot the tenant out until the situation is rectified (which will of course be a day later when they can come back and verify the temperature is back to normal).

So, I would install a vent that automatically opens and closes with temperature like this:https://www.lowes.com/pd/Air-Vent-17-5-in-x-9-5-in-Plastic-F...3.

I've been taking in so much info that I'm in the analysis paralysis phase but I'm curious how someone more seasoned would get the ball rolling with just $50k cash today. 

Put the ball in their court (pun intended) and provide the facts to the judge.

These “premium” options will rent for significantly more than a typical bedroom, and having a “premium” option in a house is sometimes the deciding factor in whether the property pencils out.Moderately important: temperature & HVAC control.