It's not Intelligence (that would be way too many), it's Intelligence bonus. Average or less (dumb fighters etc) gives you nothing, 12-14 (that most end up with) gives you one or two skill points, and it gets insulting only if Intelligence is your primary stat, especially at high levels. (Item boosts do not count for the bonus, I should make that clear.)
Int-based full casters get tons of them, but when it comes to full casters, Knowledge is not what makes them overpowered. The only ones you should really worry about are Int-based gishes: a Factotum would get all possible synergies (and can use them all!) very soon, and with Knowledge Devotion at 3rd level, he can hit like a fighter. My verdict? That's OK. He's still no match for the damage output of a dedicated tank, and it's nice to boost gishes.
Err.. I didn't get that. What minimum skill ranks?
I feel your pain. Give out more, they're never enough, and tell us about play-testing them. (I've tried out +2 skill points to everyone, Able Learner for free and a background bonus of various numbers, but not all of them at the same time.)
@All: Don't hold your breath for the Social Skills just yet. It will be a variant, not suited for everyone, and I intend to make it independent from the other rules.
Thanks again.