Hi Peter, Your space is enviable, soon I will start a similar but much smaller project. Here is something to consider before you insulate, as I recently got a smaller space ready ready for a permanent layout.
I rough wired multiple locations for 2 circuit tracs, running 14-3 type nmb (romex). I treated each Trac as a home run (single 14-3 cable between each Trac and J box) I ran the Home Run to a hidden but accesible junction box that also had a 15Amp 14 Gauge 120VAC power circuit. Using multiple and amiable Trac heads with LED spot and floods I will be able to do many different lighting scenes. The many different scenes can then be programed into Lutron Caseta switches with unlimited possibilities such as simulated dusk using your cell phone to control the out of sight Caseta switches.
I also installed 2each 4" flexible ducting from high points on the ceiling to a Panasonic 300 cfm remote fan exhausting to the outside.
Before I retired I had installed a lot of like equipment for my customers.
Anyway good luck you appear to have the talent and the space, I wish I had the same.
kevin