gafftaper, could you also show a drawing, with elevation dimensions, of section thru a typical catwalk with the hanging battens?
No open shelves, ever! Only cabinets! For fixture storage, two vertical pieces of
unistrut 10' apart, then 2 or 3 horizontal pipes between them, easily vertically adjustable as
ERS are longer than S4Pars. First location for these "racks" on the upstage catwalk, then if necessary move to the SR side. Same thing for cable except a single vertical of Unistrut with 2-4 6" U shaped cable hangers, of 1.5"x1/8"x2' strap steel, painted white with a band of white gafftape on the tip of the onstage part of the U to protect sharp edges and write what kind of cable, and possibly how many, go on that hook.
Consider painting the floor of the catwalk light gray, easier to see small items, screws,
etc., no matter how good your worklights are, and the audience will never see it. Also lets you know it's time to send a freshman up to "sweep the cats." Teach all crew members to make a choke, or lark's head, on the top handrails, with their unused "two cubits long" tie lines. They will always be handy, and won't have to be picked up off the floor. I hope you've ordered a bunch of sidearms, or 1.5" 18"-36" pipes with half-couplers to
sidearm off the offstage sides of the catwalks to hang downlights around the perimeter.
I'd keep particularly delicate, small items, like
gobo rotators, of course all gobos and
color media, in the booth storage.
Those are my suggestions. More later when I think of them.