Hi, and welcome
1,
clonedvd does support backing up to DL disc's, i think the layer break is set be clonedvd, which isn't where the original is (i think). But DVDD put's the layer break in the same place, ISO --> Read, ISO--> Write.
2, No, you can buy
anydvd and use it with any other program.
Guides and Tutorials
http://club.cdfreaks.com/forumdisplay.php?f=72
Clonedvd & anydvd forums
http://club.cdfreaks.com/forumdisplay.php?f=62