So awesome that you’re taking this all on yourself!
I myself have zero experience other than helping my step dad out with some small remodeling projects but maybe someday.
An idea on lighting... it looked like you ate going through the trouble of bolting the can lights to the beams... i was wondering why not run something else along the beams to makr that eaiser... but of course you mentioning having an open ceiling makes sense not to since you probably want it looking clean... But right now I thought... why be rigid with your lighting? It might be cool to just run switched outlets up there then have 1-1/2” (I think maybe larger) tubing running along and attach PAR lights with o-clamp hangers. They would look kinda industrial / soundstageish and you could reposition and re-angle at will.
The o-clamps are pretty versatile as well... you can hang small speakers, projectors, etc.
For putting wire in conduit I think modern THHN wire is what is preferred... no idea if Romex is allowed but would be interesting to know.