1) HPdvd200i
2) whatever the newest version of Nero is at any given time
3) hp DVD+rw discs (got a STEAL on a 25 pack for $25) , and then any name branded dvd+r discs
4) DVD videos, and the big one, BACKUPS! The original PS2 drives could only read - discs, but any made since august can read - or + r discs, all after then can read +rw, and some can read -rw. Xbox, well,
I've heard very mixed things about the disc types it can read, and it all depends on the mod you're using. Idon't know enough about that honestly to have my opinion count on the xbox issue.
5) Never. If your system can handle using a 48x cd-rw drive, it can handle even the new 4x dvd-rw drives. On my 2.4x drive, it takes me ~24 minutes to burn a whole disc, not bad at all. If you screw up a disc, it's really your fault if you're using a dvd+ drive, as only bigger name brands make the discs. For movies, you need to know how a DVD movie is structured and where to put files if you use nero, otherwise you'll need special software that lays it out. However, it's easy enough to catch on to. With dvd- drives, if you buy quality media, again, you screw up a disc it's likely your fault. The tricky part is that many REALLY horrid companies make media that flakes and is error ridden. Stick with the the named stuff, like Pioneer or Apple or Mitsui. Princo will LITERALLY fall apart, lol.
Also, keep in mind that if you get one of the 4x ppioneer drives, you need special media to burn at that fast speed, and it's expensive (comparatively). Lots of stuff here to learn, don't make a hasty decision!