Isn't A missing the rule that "it does not hurt the company?"

how many levels are there in total?

Got the question right. However, it seems like I am not too sure that I understand the question after watching the explanation video??

Causal claims can be chained together. If A causes B and B causes C, then A causes C. The A-C causal relationship is "indirect" in light of the mediating relationship to B.

you cannot "flip and negate" on the "some" or "most" arrows. "Flip and negate" (the contrapositive) is just for conditional claims.