re: What's the methane going to burn with?
I'm just reading down the line now, but, a volcano might, just might do the trick on Titan. Now, it would be great if there IS water present in the magma (hydrothermal) to determine whether or not there is in fact ground water present. Cryogenics from frozen water/H2O and it's relationship to hot magma would be just fine since it is Titan and the results would be... liquid water.
Which brings me to the question of Io/Jupiter. But that's another story.
Sorry, I'm thinking out loud (as usual).