Wow takes up surprisingly little bandwidth, nuro is right in that you'll need a decent graphics card, but the internet connection part should be fine. The boss he's referring to is the sha of anger, which is a world boss that isn't needed for progression but may cause heavy lag.

I do have a good graphics card (i built my computer for gaming) just my internet connection is shitty

Yea, I'd just avoid the sha/galleon and possibly quest hubs at peak hours, but yea, if the bandwidth is the only major concern, it'll be fine.

another problem though - roommates watching netflix like 24/7 :/

Hmm, not quite sure then, I just know that wow uses a lot less bandwidth then you think it would.

Well that is reassuring. I used to play on a 9 Mbit/s connection and i would never have any problems, even in 25 man raids and big BGs. you prolly just talked me into giving it a shot hah

MoP is very very, very pretty graphics wise, but I think if you have the graphics uber low and avoid highly populated area you should be fine. I pity you though, there's a major world boss I believe you have to kill before you can gain access to the raids(that's, at least, what I was told), and he's a 40 man raid... I usually play pretty well with lower graphics and I tend to lag during the fight with him.

Like I said and other have commented, just avoid highly populated areas and you should be fine.