Snapedom

Interesting question! Hmm, both sides of the argument seem to have merits of their own. Now I'm getting less sure about my own assumptions...

I've always thought of Severus as having attended a Muggle school, ever since HBP at least, and my main reason was because he is described as a very logical thinker, which is supposed to be a rare thing for a powerful wizard to be according to Hermione. In PS/SS we see Hermione solving that puzzle that Snape devised, which Quirrel (or Voldemort) also managed to solve so it wasn't *that* rare for a wizard to be able to handle logic after all, but to me it seemed significant that Hermione is the one putting down wizards' lack of logical sense and solving that puzzle at such a speed. Hard-working mindset aside, I think Muggle education is where she got a training in that kind of thinking processes, because Hogwarts surely never teaches anything constructive to the kids' logical thinking capacity. Yet Snape is narratively described as not only quick-witted but also extremely logical in his thinking process -- as in GoF when Harry observes that he "put two and two together as only Snape can." (Although "only Snape can" was probably just his panicked exaggeration -- I would hope that most teachers at Hogwarts have at least enough wits to see the egg and the Marauder's map and immediately know it's Harry.) Then we have HBP Ch.2, where the way Snape manipulates the conversation to dig for information while defending and reinforcing his own believability requires not only guts and quick thinking but also logical thinking abilities.

Also, if Snape had to attend a Muggle school in that kind of attire and suffer constant bullying, it would make more sense for him to end up joining the Death Eaters than if his sentiments about Muggles came solely from his resentment of his father. He did know of Lily's love for her sister, after all, and must have seen her parents too, even if it was only from a distance. But if his view of "all muggles" had already been set from his five years of schooling, it's more understandable that he completely disregards Petunia from the first moment he set eyes on the Evans sisters.

So I never thought of the possibility that Severus might have been homeschooled, but that's a very interesting idea. Certainly goes well with the level of wizarding knowledge he already had before attending Hogwarts, including possibly enough DADA talent to garner him a bad name among the Gryffindors... Although in my own view I always assumed that was just a product of his curious and studious nature, the same as in Hermione's case (only, Severus got a head start, since he could get his hands on wizarding reading material and live demonstrations -- his mom -- from a way earlier age than she).

Also, I kind of took for granted that all muggle-born children (and some half-bloods like Harry) attend their Muggle schools without much incident, even if they have random bursts of magic from time to time. Harry's magic went off even as his aunt and uncle tried to make him suppress it, but that didn't really get him into enough trouble to get him kicked out of school. And, in the case of children that don't get as much punishment for performing wandless magic as Harry did, I'm suspecting that they have greater ability to control their magic, at least when they're not too emotional. Lily could control her magic to fly off swings and make flower petals open and close: those were conscious things she did. Tom at the orphanage, too, did things with his magic that he consciously aimed to do. So I kind of thought Severus must have done fine at school as long as he kept his anger in check -- which, though, might have been a very hard thing to do, considering his temperament and probable circumstance. But, you know, unlike Harry and Hermione whose guardians were mere mortals, Severus had a witch mother. Surely if he did something too disastrous to let the matter lie, it would have been an easy work for her to hop over to the school and obliviate the people involved before it got out of hand?