Can my manager download the orders as a spreadsheet, or is that owner only?

Owner only. Managers see every order on the board all day, so nothing is hidden from them; what is reserved is turning the orders into a file, because a file can be forwarded or lost with a laptop. The owner uses Export these orders on the orders board, picks up to 31 days, and gets one row per order with a totals row at the end. Every export is recorded with who took it and which dates. The Orders & delivery tab in the docs covers the export.