To me, a booking just means "they said they would do this much business with us". It doesn't make sense to retroactively change it, because if you make bookings just match actuals, you're losing the meaningful info about the rough estimate the customer agreed to. Does this make sense? Am I missing something?

I agree with you @reptar and would say this is more of a business process issue with your sales team versus a fundamental issue with NetSuite. I would agree also that a business would want the KPI of variance between booking and actual sale/invoice. This doesn't answer any advice in NS, but perhaps try to "sell" them on better business processes...? Much luck!

We also don't use Sales Orders for the most part. We're basically doing that with a status on Opportunities. I would imagine it's related.