How I Use my Concrete Bunker

If you've seen any of my videos before, chances are that it was the one where I showed this super cool concrete bunker built into the side of a hill here on the ranch.
In that video I asked what I should do with it. Had loads of suggestions, and after this past winter managing a growing fleet of small engine machinery, I have finally landed on my plan.
Let me know what tips/suggestions/concerns you may have given my intended use!