re: Europan Ice Domes
Given any tectonic motion (due to tides, etc.) it is likely that if Europa does possess liquid water deep underneath, that there would be upwellings through cracks and the like, possibly quite recent. This study describes a very specific mechanism, but there could be many such.
Obviously, these would be ideal places to look for life traces, especially recent ones that would not have received as much exposure to space and radiation, and I'm hopeful that a probe could be sent to do it. It would sure be easier than trying to melt through miles of ice to get at the stuff underneath.