<p>I'd say researching/gathering info/whatever you want to call it about your roommate to this extent is probably going to harm more than it helps because it already gives you a false preconceived notion of YOUR relationship with your roommate before you even have a chance to let that person give you a proper introduction/first impression.</p>
<p>Even if your roommate is a ******bag to others/online/whatever, it doesn't mean you two can't get along as roommates. </p>
<p>Everyone has the worry that the person they room with will not be compatible, and this is normal. I'd say that the best thing to do is to discuss some important ground rules with your roommate so you guys don't wind up blasting off at each other later. Make sure you guys are aware of each other's lifestyles, and that you respect one another and figure out a way to be as compatible as you can given your differences. If your roommate has a girlfriend, for instance, you would probably want to discuss what to do in the event she comes over, and that sort of thing.</p>
<p>In the event that you guys are not working out and you don't see it being a healthy rooming arrangement, you can always switch rooms. Most roommates, I think, generally get along with each other, even if they aren't friends. Most roommates, I think, don't make it through the year without a few small clashes, in some form (usually very, very small grinds, such as leaving food out or getting water everywhere in the bathroom, etc -- "small" things).</p>
<p>If clashes become comparably worse than that, then you could take further action. If he's constantly sexiling you, or playing loud music into the late hours of the night, or putting you down/trying to be overly controlling of rules/schedules, or whatever... then it'd be justifiable and appropriate to get a little more aggressive and suggest that you two find another living arrangement.</p>
<p>But, I'd still advise you to try to meet your roommate with as much of an open mind as possible. Preconceived notions are often flawed, and I can't see them possibly being of much use to you here. Always keep in mind that your roommate is just that -- a roommate. Whether or not you two choose to pursue friendship is another story. As long as you guys can live together in the same place and not have any serious clashes, things should be just fine. I hope everything works out for you!</p>