The ocean crash is a good theory. However, there are a few holes in it. For one, unless the aircraft made a perfect open ocean landing in the dark there should have been some debris somewhere wash up. None has been found. Also, with 14,000 gallons of fuel on board, if the aircraft broke up, there should have been a sizable fuel spill and none was spotted. An enormous effort was launched by multiple governments to learn what happened to the aircraft. If there had been a large fuel spill, logically one would expect to see some evidence of it. Granted, the search began three days after the aircraft vanished when the owner was able to get the US govt to sit up and take notice. But the US govt was not the only govt looking for the aircraft.
Scrapping the aircraft for parts is another definite possibility. Given N844AA's sudden celebrity status, getting rid of it makes a lot of sense. But none of those parts ever showed up anywhere and people were watching for them. Plus, there are credible reports the aircraft was spotted years later by an airline captain and his first officer. These gentlemen had the opportunity to study the aircraft at length and both say the tail number, although the paint was removed, could still be read because of differential corrosion.