Traveling by air certainly limits one's ability to pack much in the way of fishing gear, but my family stumbled upon telescopic open-face rods/reel combo's at Gander Mountain years ago. I suspect the intended use for these poles is for someone fishing on a kayak or jetski, but they're also perfect for travel. Years back, my father and I would walk the trail from WL to FW to a canal stemming from Bay Lake. In this canal was a large pump that seemed to aerate the water. Needless to say, the fish were very active near this pump, and we landed a few nice largemouth bass with plastic worms. In more recent trips, we have found the pump not active (I'm not sure if it is timed, or if it is simply no longer functional).
In any event, we often see folks in the FW area fishing. You used to be able to buy worms in the bike rental post at FW (maybe you still can), so I have to assume that it is acceptable practice. I recall hearing that so long as you weren't fishing from a dock (i.e. - heavy foot traffic areas), then you were OK. If there are any written rules against it, they sure don't go out of their way to make them known. Usually, in the world of Disney, if you're doing something that is against the rules, they are pretty quick to set you straight.