This is an ice maker box which is currently nailed to a firewall (which the drywall I think was partially glued to originally - I don't see any screw holes into the firewall at least from where the drywall sat over it).Is replacing the ice maker valve box something I should consider having a go at myself? 

Appreciation is always icing on the cake and it will happen eventually depends on the economy.

They don’t want to be calling us a million times over a broken ice maker (sure, insert some anecdotal story about a tenant that never stopped calling a landlord over petty issues.

Those who are not are getting creamed right now.

Appreciation is only icing on the cake.  

If you do decide to paint, you can sort of "prototype" the color by going to the fabric store and getting a few yards of different colors of fabric - pure white, cream, whatever you think might look good. 

Even if you lock them up all they have to do is place a bag of ice on them to cause the heat to kick on and stay on 

My primary residences have brought me many hundreds of thousands of dollars in return from forced and market appreciation over the years, and that is icing on the cake in addition to giving me and my family a nice place to live.

If they slip and fall on ice and it is their duty to remove snow and ice the LLC will help if they sue. 

It still needs a dimmer switch installed so she can sit outside and not feel like she's on a stage.Top picture gives you an idea of the lights and how they look at night, bottom it's complete (no stain yet)I'm thinking an earthy green, cream/yellow trim with a dark red door.