Cameron,
I respectfully disagree with your take on the interpretation at the NHFS website. It says nothing about B1 moving in situation 7A, it only says that they have 1 foot on the boundary line, and it is therefore to be called a block. If the movement were the key here then in situation B where the player only has a foot "over" the boundary line but in the air, then neither A or B would be a block. The interpretation is specifically referring to having a foot on the line, and the interpretation is that this is to be called a block if seen, no ifs ands or buts...with that said, I do think that intentionally contacting an opponent ie running his @$$ is maybe another can of worms, like a flagrant personal foul....which might bring us to a false double foul

wooooo hoooooooooo.. coaches everywhere will love us right Hawkscoach ;p