IMHO----I personally think the Japaneese were fortifying the Mandated Islands. Alot of work was going on at Truk, as we have seen. I also think that is someone were to have gone there, and was captured, there would not be any record of their demise.
With that in mind, IF AE did somehow manage to find herself at Kwajalein, or Truk, or even Saipan, I dont think we would know about it. Even as famous as she was, Japan cerainly would not tell the world that they captured her. Even in 1937, when our military wasnt ready for war.
I dont think she overflew the Marshalls. She was on course, and on schedule as she passed over the Gilberts. To have made a 90* left turn NORTH to fly over the Marshalls, a LONG WAY AWAY, then try to make it back to Howland, stretches even my vivid imagination. NOT to say that she didnt end up at Kwajalein, Truk, or even Saipan, because evena s far fetched as it sounds, anything can be possible, until proven otherwise.
Stephen does bring up and interesting theory on Japaneese testing things. Yes they could have sent ships out, testing the waters so to speak. (Not sure when Truk actually became operational, but I dont think it was in 1937). But, that doesnt mean that Japan wasnt out there. It is possible that AE DID land at Niku, but wasnt there when the search overflight took place. But, I think that IF she were to have been removed from the island, (unless it was on a submarine) a ship would have been noticed by the searchers.
I'm not supposed to speculate---so I wont. But you get the idea--
Tom