It's too purty to not do it.

Nothing is "safe" in the hands of an unsafe user. If you treat your discs well, there's no difference between printed and unprinted. It's true there have been reports of printers mis-handling discs, which you can read about in this forum. By and large it appears to be due to faulty printers, not due to design issues. The Canon printers all use the same mechanism for disc printing, and are designed to not touch the printable surface. Damage to the recorded side is pretty rare, and usually due to mis-handling by the user or a flawed disc tray. I've printed hundreds, not a single problem.