Marcello Monogatari is very wrong, since there's furigana. You can read it up on wikipedia if you don't know what it is:
http://en.wikipedia.org/wiki/Furigana
Ignored furigana a very common mistake you will find on the internet.
As ugly as it is, it's still the official japanese romanization for the product and it should be used. It's not a matter of liking it or not, it's literally the official title.
If the manga was licensed in English and had another title, you could put that in the 4th line, but the display title should still be the japanese romanization.
As for the artist, CDJapan is not a good source for romanizations. We have the artist page right here, I assume the reading comes from english credits on an official release:
http://vgmdb.net/artist/9800
EDIT: for example here, last song:
http://vgmdb.net/db/covers.php?do=view&cover=201515