Printing without spooling

Can't be utterly definitive, but I very much doubt it (on any platform). Spooling just mean caching ready for transmission to the printer or server. Caching is necessary to ensure all the info reaches the printer whatever happens in the space from pressing 'Print' to the printer receiving the data.

Only if your printer can be fitted with a lot of RAM of its own. Spooling to the hard drive means 'spoon feeding' the printer with info at the rate it can digest.

OS X does not have the foreground/background options that OS 9 did.

Even in OS 9, large print jobs were written to disk.

If you disable spooling in OS 9 the only thing you achieve is locking up the Mac until the print job is complete.

OS X does not have the foreground/background options that OS 9 did.

Precisely because of the much improved memory management of OS X, whereby it becomes a non-issue.

But my previous comment about RAM in the printer itself still applies.

In OS9, "foreground Printing" simply means that the print cache ('spool') has first call on the available memory.

OSX doesn't use memory in the same way, so the print cache works in the background and you should never see any problems unless you have very limited RAM (in which case you shouldn't be running OSX)

"spooling" (caching) will always occur unless the connection to the printer is faster than the bus speed of the computer, and the printer has sufficient RAM to store the job without relying on the computer's RAM.