While I agree about BHO Sr probably not being in Boston at that time, what what do you mean about available routes? I find it hard to believe that in '61-'62 time frame somebody wasn't flying from Hawaii to Seattle, or Vancouver which is pretty nearby and wouldn't change the numbers much, I was just responding to your comment about it being quite a detour. It's not. Airlines fly great circles because they are the shortest route between two spots.
Incidentally that website doesn't just use the spherical earth approximation with a closed form solution, which really isn't that great over a couple of thousand miles distance. It uses the WGS-84 ellipsoidal earth model. The Spherical model is still pretty good out to 600 miles or so, and very good over a couple of hundred miles. Practically speaking even the spherical model will probably let you at least find Hawaii, even from Tokyo or some Indian port, it just won't put you right in the harbor mouth.
This State of Hawaii link indicates that by '61 several airlines were servicing multiple US cities direct from Honolulu.
When I took my wife to Hawaii in 1980 (from Seattle), either there was no direct Seattle to Hawaii flight or there was only one that got there too late to get to the outer islands. I am not a particular go to Hawaii fan but we have a number of friends who do; and a client who has a division of his business there; the routing people talk about is through San Francisco. In the early 1960's, it would not surprise me that San Francisco was the only route.
So yes, Seattle would be out of the way in airline routing to Boston. Plus which the Boston fairy tale has a problem with the fact that Obama Sr. wasn't there until a year later and it isn't likely he was there much earlier because he was also considering an alternative education grant that would have been sufficient to pay for taking his wife and son.
When it was over there were SEVERAL airlines flying the Pacific. In 1961 there were so few airlines flying the Pacific, and so few flights, that it was common to take hops across the Atlantic and Indian Oceans to East Asian ports to then access Japan and Korea.