Is it permissible to undergo liposuction and the accompanying body modification, and what is the ruling on traveling abroad for treatment in specialized obesity clinics that may require exposure of the 'awrah?

There is no impediment to removing excessive fat by the method mentioned, even if it is for the purpose of improving one's appearance, because these are incidental excesses on the body, and removing an incidental excess is not considered an alteration of Allah's creation.