Since he's 30, and you talk about 'when we were younger' in reference to him, and talk down about his friend who's already 21(!) and has not gone to college, it sounds like you're over 18 years old, right?
And if so, I'd suggest that you can mitigate most of these problems you speak of (especially since it doesn't sound like you actually *care* about your selfish brother, you only care about the negative ways his actions impact you) by simply moving out of your parents house.
And I'm sorry but unless you're like trapped in a small car with the windows rolled up, there's no way that being around someone smoking pot is making your eyes and throat burn.
Honestly, to me, you sound just as self-centered as your brother, you just happen to not like to smoke pot.