Think "Bit" and "Coin"
I almost like the sign that the Room service guy does for a Tip in Home Alone:
https://www.youtube.com/watch?v=ae2oNrFz2J0
That actually is the sign language sign for money. But I saw that in the US it's different. Sign language has different dialects depending on the geographic location. But I think the sign you are referring to (and the one from video 2) is recognized around the world.
That would actually be great, also because that would probably mean that bitcoin adoption has become widespread (until then those kind of specific utilities will not become available/profitable).
I didn't see that your second video included that same sign for money. I like your two ideas, but they're kind of hard to do at first. Do you know what the sign for "Bit" is as in "Computer Bit"?