I know i haven't posted here in a long time, but I had to write something in the hopes that it may, in humility, help clarify things.
St John Maximovitch of Shanghai/SF the Wonderworker IS INDEED a saint recognized by the OCA. On my 2004 OCA wall calendar, his name clearly appeared on July 2nd. Not to mention the fact that at Great Vespers (in my OCA parish no less), his name is clearly read with the other saints' names. As I am aware, there is an OCA monastery in Calif. and an OCA parish in Georgia that bear his name. It appears to me that it's a "no brainer": he's a saint!
As far as the sanctity and martyrdom of St Juvenaly of Alaska, there's an excellent book called "Alaskan Mission Spirituality" I think that details the history and development of the Russian mission in Alaska from the 18th century to modern times. It's an excellent read. Auther is Fr. Michael Oleksa I think. In it, he recounts the lives of the Alaskan saints (St Herman, St Peter, St Juvenaly, St Jacob, St Innocent are the ones I can remember right now) and provides good evidence toward St Juvenaly's martyrdom. You may find it helpful.