So at school a couple of days ago, my friend's friend introduced herself to me and she was talking to me about how she's taking a few religious studies classes including "History of Satan" and "Comparative Myths" classes. She told me how her teacher knows a whole bunch of languages and has studied many of the religions of the world. She also said however that Jesus isn't the whole "loving, peaceful" man that were lead to believe, in fact, he was a thief, a drunk, a pervert and a violent man. She also has said the same of Muhammad but that's a different question. Anyway given this context, do Historians see Jesus as a peaceful man, or violent person?
No, generally not.
Firstly, and as an aside, "knows a whole bunch of languages" does not make one, by itself, a reliable source or scholar. It definitely helps, I have quite a few up my sleeve, but serious scholarship is what makes for serious scholars.
Anyway, on to the Jesus question. I'll come to violence last, because it's probably the most likely of the four unlikely claims.
Honestly, I don't know where this teacher is getting the 'thief, drunk, pervert' picture from, because practically no account of Jesus gives such a picture. Not the canonical gospels, certainly, but not the non-canonical gospels either.
The canonical gospels (Matthew, Mark, Luke, John), do portray Jesus as engaging in wine-drinking, and generally being fairly pro-feasting and partying. But they don't have a single account of him either being drunk or promoting drunkenness. So you have to at least go beyond the basis of the text there to suggest it.
I honestly don't know where the pervert claim is originating from. Or the theft claim.
The real problem here is methodology. The question one generally ought to be asking is, "given the documents we have, and the Jesus movement that arose, what is the best explanation for its causes and origins?" To which, a morally rigorous apocalyptic messianic figure is a reasonably good explanation, but a morally problematic charlatan is a much less believable fit.
Now, what about violence. This is proably the kind of view put forward by someone like Reza Aslan in Zealot: the life and times of Jesus and Nazareth, a book widely criticised in historical Jesus studies. Aslan's (not unique) thesis is that Jesus was a zealot - a nationalistic revolutionary with a violent streak. The major issue with this theory is that while there were messianic figures of this kind in Jesus' chronological context, there's no memory within the first few generations (the period of writing the New testament and other documents) that preserves and promotes this image of Jesus. In which case you need to hypothesise that early Jesus followers deliberately and collaboratively erased that recollection of Jesus and constructed a Jesus who was apparently pro-peace and opposed to that revolutionary tradition. Again, which is theoretically possible, but for which there is no evidence, only speculation.