As for the hi-speed USB question, yes, all USB 2.0 peripherals are backward-compatible with the older USB 1.1 standard, so as long as the burner adheres strictly to the USB 2.0 specification, then it will be fully compatible with USB 1.1 ports (although DVD burning at USB 1.1 speeds is virtually impossible -- CD burning is possible, but painfully slow).
Pretty much all CD/DVD burners are "compatible" with OS X, but only a few will be "natively" supported for iLife burning (iTunes, iPhoto, iDVD, etc.). 3rd party burning software like Roxio's Toast Titanium should be able to see and burn media on that drive... you just may not be able to natively burn media from Apple's iLife suite.
There is a piece of software called "Patchburn" that adds support for unsupported burners and it may help in this situation. It may help to find out if Patchburn supports your burner.
