But a few have remarked to me that looking more closely the hand/arm look too small to be Hamill's (it looks like a woman... THAT could be Carrie Fisher), while what you suggested was a shot of Leia I rather think is a shot of the young female lead receiving the lightsaber.

It could make sense.. .Leia got post ROTJ a lightsaber from Luke which she never trained with/used, but as she suddenly senses the Force in her daughter and sends her to find the reclusive Luke to convince him to train her/return to Leia because the force is "awakening", she gives her the lightsaber That would be very SW... if the lead/jedi trainee character is the girl, then the "quest giver" figure (ie: the Ben character, if you wish) needs to be her mother or a mother figure, sending her to "Yoda" (Luke). This would also be a replay of ANH to an extent, with Leia sending someone on a mission, with R2.

It wouldn't be too mythological for that figure to be a man, for a girl hero. It would also make sense for Lucas to have toyed with the idea of a female lead for the last trilogy, as the Hero's journey and its archetypes are different for women, and unlike the male ones with the OT/PT, he had not exhausted them yet with Leia and Padmé.