Re: Why do wizards hate sorcerers?
Wizards have to invest in their powers. They take longer to learn them, have to work harder at it, and need to pay money for nearly every spell they learn (plus possibly having to buy a spellbook, although 15gp isn't terribly expensive compared to the cost of armor or magic items). They've struggled and sacrificed for the power they wield, and then some doofus waltzes in whistling and casts a spell as if it were no harder than scratching his butt. Naturally the wizard seethes with spite and envy at someone being so lacksadaisacal and disrespectful of something he's sweated and struggled to achieve.
Conversely, Wizards are noticeably more powerful under most circumstances (the distinction between spontaneous and prepared casting is a lot like the distinction between warrior talent and magic; in theory a Sorcerer or even a Fighter might be balanced with a wizard because they're better able to function in non-ideal circumstances, but nothing stops the Wizard from making his circumstances ideal the vast majority of the time, so the balance isn't really balanced), and that means they have a dominant position. Which means that just like in any other hierarchy, while they might want to train disciples to follow after them in time, they certainly do not want people nipping at their heels before they're ready to give up their position. Thusly, sorcerers are rivals, brash young talents threatening to usurp the wizard's mastery of the arcane. They don't want the competition, and they act quickly to squash it, much the way McDonalds would react if a new burger chain "O'Tolley's" was opening up and trying to weasel in on their market: they'd pour money into an advertising blitz and try to remind the buying public who the best burger-maker in town is, and spellcasters are in the same boat (since their services are also for sale).
Between the perceived challenge to their dominance and the insult of someone else having it easier, if not as good, it's perfectly natural that the wizards would be cheesed off and bitterly determined to squash the upstart. Though it's a bit surprising that the sorcerers don't return the favor more often; I figure it may imply that they're more analogous to the Young Turks than the Old Guard, being more proactive and positive focused, trying mostly to make a name for themselves and thus only indirectly interested in defeating the competition.