Re: The Hands. ....on her mothers side? I'm going for a Moffat glove'ed power play on that one and it won't add jup to much in the way of a revelation.
Re: The Underground Tin....This one is easier. The Doctor carries his jammie dodger's around in a tin he got once...he's simply brought it to Victorian England because they don't have jammie dodgers there yet? Seems the likeliest reason for it.
Blogtor Who (who are still maintaining their "wall of silence" about their slipped 50th Anniversary post that mysteriously disappeared that Cameron is now claiming he never posted)....have pointed out that the image has been removed from the official site now....and they think it has less to do with Vastra's hands or the tin....but the initials on the doorway.
You could apparently see her human wrist in another shot and the person who noticed notified the Beeb and then took it down, and then re uploaded it with the wrist portion painted (photoshopped over)...and with their thanks for the oopsies.
So it would appear this is all sound and fury...ect.ect.