Okay, well, Bobby has cooled HEAT beams. Literal beams of heat. He could take the Torch, and even if the Torch destroys earth, all he has done is killed himself, and left bobby floating out in space.
'Bubbles' of force won't work on Iceman. Considering that a force field stops...well....force. Consciousnesses don't exude it. He could go to any other water on the planet, including that inside of Sue Richards. It would kind of be like teleporting out of the Field, considering that he doesn't have to TOUCH water to transfer from/to it.
Magneto manipulating electrons in the water will do little besides make the water ionic. Besides, what is he going to do when bobby resides inside him? Or when he is getting flash-frozen? Hell, it was said that bobby could travel from boston to atlanta before someone could pull the trigger of a gun. I think he has the speed and maneuverability advantage over Magneto.
As far as the Flash goes, that's been argued on the Iceman/Storm vs. Aquaman/Flash thread. Go check it out. Igniting moisture on fire (I didn't know that water could burn...what is water's flash point?), even if it were possible, would be ineffective. Bobby has existed as vapor plenty of times. Besides dumping every droplet of water on the entire planet (including that which resides inside the Flash's own body) into the speed force, the Flash doesn't really have much to do to Bobby.
EDIT: As far as 'destroy the planet' arguments go, what kind of speed are we talking here? Bobby can INSTANTLY freeze their bodies. At a whim. Also, destroying the planet would hardly work, unless you collided it with Anti-matter. I mean, if the planet/atmosphere is gone, it will fall to pieces, but there will still be ice, it would just now be floating in space. So, unless you find a way to destroy matter, or change all the matter on the planet into energy, you'll be hard pressed to destroy Iceman.
Hell, Iceman could even simply allow Magneto/Invisible Woman to do this, and all the while be INSIDE them, allowing them to believe they have won. As soon as they get to wherever they have decided they'll live now, Bobby flash freezes them, and uses the moisture from their body as his new construct. Following, he uses moisture inversion on whatever planet/asteroid/ship they got to, and uses all THAT water to create his new, Ice, kingdom. 😛.