You can usually find vocal credits on anison:
http://anison.info/data/source/24080.html
About the title, it's ok to add parts that are just on the obi/spine, especially if it makes the title a little more descriptive.
As for the other printings, you can add them using Edit -> Add a Child Album. Usually you want to make the one that came out first the parent (in this case the vinyl), but if the release date are somewhat close to each other, it's ok to make the CD parent so that the Side info from the vinyl/cassette doesn't propagate to the CD entry.
If you have some better (maybe not watermarked) pictures for the vinyl, feel free to submit them
