Mages - 3 second stun, 5 second silence, 6 second snare, 12 sec slow (costs at least 8 talent points to max duration on the ccs)
Prophet - 2 second stun, 3 second silence, 3 second snare, NO SLOW (costs 1 (ONE) talent point)
Ranger - 2 second stun, 3 second silence, 6 second snare, 3 sec slow (costs 3 (THREE) talent points)
Sin - 2 second stun, 5.5 second silence, 3 second snare, 6 sec slow (costs 6 (SIX) talent points, with a built in teleport included)
Warrior - 3 second stun, 4.5 second silence, 6 second snare, 8 sec slow (costs 8 talent points, with a built in charge)
Templar - 3 second stun, 3 second silence, 3 second snare, NO SLOW (costs 2 (TWO) talent points)
So mages need to spend a lot more talent points, but aside from their slow, it's not like they are the only class that has longest duration disables. Other classes only spend a few points to get their disables maxed.
Boiling blood is an OP dot... emphasis on the "AN". meaning 1 dot. meaning it can almost always be removed with serenity. Rangers have 2-3 dots, and you can't even remove some of the assassin dots at all. Not to mention it has a long-as-shit casting time, for PvP. Other classes will already be on top of you by the time it finishes, at which point you die. And it costs 4 talent points. After taking talent point costs into consideration, it is actually quite expensive and silly, considering it can easily be removed. Not to mention the long duration, envenom works better since it does it's damage really quick, making it harder to be removed.
And sorcery can benefit into healing. Too bad healing is not based on sorcery only. Healing values are roughly 16% sorcery, 16% essence, 16% gear, 50% talents. And a pvp mage has no healing talents. The only "heal" you actually can rely on in pvp is cauterize, and even then, it heals only a fraction of a prophet's heal.
And why are you even saying that an ungeared, low level mage can win against a higher geared person? That much is obvious. It is possible for anyone to win against anyone. With enough skill and depending on circumstances. Besides, the buff you get against higher level players is quite decent. A low level with the buff is already as strong in stats as a max level that is only half geared .