(I'm going to continue the email conversation between Pavlos and myself here, so he can share his extensive knowledge of Greek names with the rest of you :) )
Katherine ~
Is there any evidence that Saint Aikaterine's name is related to the older Greek name Hekaterine?
Incidentally, I could not find any reference to the name Hekaterine in the ancient Greek world, though I did find similar names which are presumably derivatives of Hekate. For example, the masculine name Hekatodoros "gift of Hekate" was common. Could Hekaterine be a similar derivative? Maybe in combination with *erineos* "fig tree"?
Cassandra ~
You suggest that it comes from *kekasmai* meaning "to shine" (unfortunately the online Liddell-Scott does not list this word). Do you mean that this is the first part of the name, with *andros* "of a man" forming the end?
Herod ~
From Herodes. You suggest derivation from *hero*. Would it not more likely be from *hero* (or even Hera??) + *oide* "song, ode"?
Thanks for clearing up the Helen mystery for me! The three names listed above are the last that I have questions on.