People have different boundaries when it comes to what is and isn't personnaly acceptable to them, particuarly when it comes to relationships. To some people, smoking quite a bit of weed or talking about 'the hottest girl' is fine and to others its not. I fall into the latter camp, as it seems you do.
Because of the fact that this doesn't seem acceptable to you, it seems you and him differ with regard to what is/isn't okay. Although you could give it a go in trying to change these things in him, it could be like pushing water uphill doing so and if I were you, I'm not sure trying would be worth it. If nothing else, they'll be arguments later on down the line about it.
What you do is perhaps hinged on how much you like him; if you do like him, you should tell him that referring to other 'hot women' and the excessive (in your opinion) weed smoking irriates you. He might be prepared to tone it down a bit. Of course, if he doesn't want to then so be it and you should move on in your seperate directions, but if you like him, I think its probably worth a go.
If you're a bit blaise about him, then I wouldn't bother going to that much effort and just chuck him and enjoy looking for someone else!
Good luck!