satellites usually have a canister of compressed gas and a series of vents to adjust their orbit for their projected operational life, so, yes, if the sun fuses their circuits and/or power supplies they stop adjusting and will eventually fall back to earth
yes, moving magnetic fields induce electric potentials in loops of conductive material, including liquids but in the case of the ocean that current is just going to flow straight down to the positively charged earth below, salty solutions are a lot more electrically conductive, in fact pure distilled water is so non-conductive i have read of cases of people using them to cool overclocked computers