But then you would let hundreds of thousands die, just so that you don't infringe on their right to not wear a seatbelt? Don't we have a moral responsibility to look out for one another's well being?

I assume you agree that it is only after a certain age that one acquires these rights you talk of. So, there is already the implication that good judgment is required.

I think the law has to be pragmatic, and to that end talk of innate rights loses some of it's value, especially when used so broadly.

Paternalism (Stanford Encyclopedia of Philosophy)

That's a good article thanks. It seems like the overzealousness of the current drug policy stems in part from "moral paternalism", and the discussion here is what kinds of paternalism are justified. The soft and weak variations seem relatively uncontroversial.

Presumably it is argued that they are not aware of the potential risks. Although I think you would have to modify it for a more specific definition of "awareness". A 14 year old can be taught the facts, but the "risk taking" part of the brain is still developing in teenagers (supposedly), so one would argue that they aren't well equipped to deal with risk.

Is it morally permissible to aid a person in suicide, as long as the potential suicide victim is aware of the consequences of his actions?

Whether or not any collection of people decide to allow or prohibit such a thing should depend on the extent such would damage or enhance the individual the larger community - it's all up to them and what they collectively decide.

... and that would come down to a question of how much and what kind of damage do these pose. The more destructive to the community, the greater one should be prohibitive.

... or so I think

Me thinks we need to apply this same standard to politicians & bankers ?