b) It's legal speak mentioning "you cannot create a new account" but it doesn't say you can't try to fix the problems about your existing account. The problem is there is nobody to reach for mistakes or downright violations from Google's side. It doesn't work to help people with good intentions realizing their errors.
c) It's not mentioning that you will forever be blocked because you misrepresented your age for whatever the reason (just an unaware click is enough).
If Google was actually serious in enforcing the policy, they would just check any detail that could trigger this user could be below 18 years of age. As you read here, they don't spend much of an effort to avoid this scenario. AI works just to block you, not to avoid your downfall.
d) I wonder Google informs kids this much before making money on free content they upload on Youtube. It's not hard to see this is one-sided exploitation in business sense.
So... pretty clear, yeah.