I feel really bad about wanting be friends with this guy...?

Well I know this guy who's my age but he's in high school because of his stupid birthday x.x Anyway, I know him because my mom is his moms counselor >.< It's really weird since his mom is actually pretty normal she's just stressed because well her son is a druggie. I mean I live in a crap town and probably 70% of the kids do drugs anyway but even my dealer friends think this guy does too much drugs. Strange thing is he's really quite smart and put together. He actually functions on a day to day basis completely unlike most of my friends. I mean I hung out with him the other day and I completely didn't expect him to show up. But he did and he even remembered it when he got home. On the other hand he definitely does a lot more **** than most people I know. My friends and I have this friend Norman, and we consider him our really stoner friend for the most part. Like we're only in grade 9 but Normans been smoking weed since 5th grade, and he started doing a lot more stuff last year, including dealing. Even Norman thinks this guy does too much. We kinda don't know what to think about it, since he has a pretty bad reputation for being down for almost anything that'd get him high o.o. Really the reason I feel bad about this is because well...I DO like him as a friend he's cool but in some part of my mind I feel like I'm just observing him, like I want to figure him out so bad it's like an experiment. He feels...disposable. I don't really know what I should do if I feel like that, I mean should I not talk to him or just continue trying to be a normal friend? I also invited him to my party this Saturday so I can't really ignore him really fast. I'm sure he wouldn't really care if I stopped talking to him.