I looked at all kinds of flooring options when I built the new shop, epoxy, tiles, garage floor tiles, box store sealers and finally went with a commercial concrete densifier, which hardens the surface of the concrete and provides some short term spill protection. The concrete contractor offered to get it and apply it for me at cost, cool nothing for me to do. He over applied it which created a crystal like "growth" on the surface because it is a lithium based product that reacts chemically with the concrete. He felt bad so I got a free application on the garage portion of the building. I had to scrub off the surface with black floor scrubber pads, (borrowed the scrubber from work) and got a very nice semi gloss finish to the floor which does not dust and can be swept and mopped. I waited till full cure of the concrete and added a couple coats of a compatible sealer to the floor for added stain resistance. The more I sweep and use the floor the nicer the finish gets. I am very happy with this easy to do and maintain system. No marks from moving machines in or material around. No marks from hot chips or oil and at any point any type of flooring can be laid over what I have. Reasonable cost and easy to apply.
FYI the densifier used was specifically formulated to be applied the day of pour. Many are not, which allows the same process to be used on concrete of any age. Floor must be clean but again that process easy. bucket and brush, rent or borrow a machine.
Drop me a note if you want some more information. Looks like a great space, window is great for light and I think a larger sized bathroom type exhaust fan would work great to remove any fumes from the area and can easily be removed to convert the space back to another use.