Mr. Brock, you are correct that the maximum penalty of life is in the more aggravated circumstances for human trafficking, and it's 14 years in the circumstances where the aggravating circumstances are not established.
As to the second question, I would point you to the Supreme Court's decision in Friesen that talks about maximum penalties as not necessarily being reserved for exceptional cases but where, as the court describes it, they're warranted.
Your more practical question is the following: Are life sentences being imposed in human trafficking cases? I cannot recall a decision where that is the case, so I would have to confirm that, but I don't believe so.