Like Wildwood says, we do almost exclusively masonry construction, so we know from nothing about framing, studs, etc. Where drywall is used (eg to divide a space) extensive use is made of lightweight steel profiles. The drywall itself is fibre-cement. I have no idea of standard spacing, but plywood is rarely used for this application. Good quality plywood costs a fortune here, whereas drywall or manmade board is more affordable.
Our affordable timber (pine) generally grows too rapidly (large annular rings) to make it either stable or suitable for much other than roof trusses.
I understand things to be different in Australia, where residential construction is more wood-based, but I do not know whether the building technology is the same as in North America. In Australia they can also uplift a house and put it down on another lot - we can't.
BTW, I can understand why the price of good timber is so high here (mostly imported), but what the hell caused prices to spike so much in the USA and Canada?