[willndmb]

1
either way works, i personally think the img is easier and safer
2
not sure about dvds, but yes cds do that--even though they are digital they still do loss a small small small amount on each burn
3
decryptor requires a img file i thing, to copy and paste the folders you would need something like nero
but the img is safer and easier imo and they both would take up the same amount of space so there is no winning there
you can also set decryptor to delete the img after burn if you want to just rip and burn and not have the img sitting around