(Not a teacher)
Although the two sentences as written are heard in informal speech, each is a perfect place in which to use the English subjunctive, which simply entails replacing "are" with "be" in both cases:
It is imperative, though, that youth be aware of the risks in advance.
While the rate of injury is extremely low, it is important that precautions be taken.
Adding "should" is not necessary, as it is implied in the subjunctive construction.
Student or Learner