There is plenty of evidence for liquid water under Europa's ice surface
Go read Richard Greenberg's new book Unmasking Europa for the details.
http://www.astroengine.com/?p=3833
I bet if you told a few Europa experts that they were acting on faith
rather than science, you would get some very interesting and pointed
responses.
It makes me question if you understand the difference between the
two disciplines and if there is some other underlying motive here, like
why you are scoffing at such an idea.
And why introduce something complex into the idea when liquid water
will do just as nicely, not to mention most outer planet moons are made
up of water ice to begin with.