Speaking of Arwyn, it was Arwen who was Aragorn's enamorata. Arwyn is a Welsh name and the Y is properly pronounced like the I in it. There may well be some non-Welsh speakers who pronounce it like a long I but that's no more the "correct" pronunciation than is "Kate Linn" the "correct" pronunciation of the Irish Caitlin, (cat leen).
Thanks for that bit of history, I was actually wondering which syllable is stressed in Arwyn, because pronunciation seems to depend of stress, if Ar-is to be long vowel [aar], then -wyn has to be unstressed, hence y->[i].
But as for myn and myne, we have only one syllable, so no stress factor. I propose to find other examples of short words with _y_ structure so we can see if y is ever pronounced [ai]
