Oh.... By the pics I thought the fingers were connected to the hand with ball-socket joints....... Are those joints in the 4th pic really hinges?
I beg to differ about articulating the thumb: it would contribute to realism as much as the other joints in the other fingers, specially in the hand that doesnt carry anything.
Also regarding the joint of the thumb to the hand: it really shows in the 6th picture, and doesn't look good at all. I believe that the thumb should be more integrated into the hand. The part of the thumb that goes from the stem to the wrist should be a fixed protrusion of the hand, into which the rest of the thumb should be linked by a ball-socket.
Even though I like your hands, I am getting more and more perfectionist: in the 7th and 8th pics it can be seen that the hands are too skinny with respect to the forearm. At the wrist, the hands get really "delicate". To look more robust and powerful they should be bulkier. I think you still haver plenty of empty space in the hand compartment, so you could make them thicker.
I know you want to be true to some comic or design you like, but I firmly believe this proposals would improve the product.
Regarding the white color in the pics, which is noticeably whiter than the rest of the valk: can I assume you'll offer a color matched version, when you ramp up productoin?
Regards,
m