The inkjet printers that print on CD/DVD are a royal pain. They take forever, use a lot of ink, and take forever to dry (and smudge easily before so). I doubt you would consider it more convenient than printing to paper labels and affixing them.
I'm wondering what information you're basing this on, because everyone I know who's printing directly onto DVDs (myself included) wholeheartedly disagrees with you. I have a Canon PIXMA 4000, and I've printed over 75 full-face DVDs without having to change a single ink cartridge. The DVD prints no slower than any paper label...or any full-color image, for that matter...and comes out looking much nicer. The ink is dry within seconds on most full-color images, and pretty much instantly on plain text labels. No bothering with centering and smoothing out air bubbles -- and, although you can technically affix a paper label to a DVD, it's a horribly bad idea. The lasers that read DVDs are much hotter than those that read CDs, and paper or non-clear labels can trap the heat inside the disc, causing skips, hangups, etc. Glossy labels are only slightly better, as they allow much of the heat to escape without damaging anything...but they tend to bubble up after playing for extended periods, and they cost about twice as much as the blank DVDs themselves. With printable DVD-Rs costing no more than standard DVD-Rs, it's a no-brainer.
LightScribe is a novelty. The burners are more expensive, the media is more expensive, and you get an image that looks like someone spilled gold flake on grayscale clipart.
Speaking of which, I'm under the impression that if I Rip a true DVD (for backup purposes of course:lol to a dual density for highest video quality, that it will play on standard DVD players. Can anyone confirm.
In theory, yes. However, some standalone DVD players have trouble recognizing the DVD+R dual-layer format. The solution is to use a DVD burner that will allow you to set the "book type" of the discs to DVD-ROM. This makes is much more compatible with older units. Google for more information.
Are there full coverage dvd's that are printable?
Sure. Newegg.com has plenty of them, from different manufacturers.