I've said nothing about your character, except that maybe you're a bit thin-skinned. The irrational posts were the ones where you flew off the handle in multiple posts. Or, as Mark called it, got a bit "touchy."
That aside, if you want to actually discuss the topic and can avoid getting so slighted and angry, here's my thoughts:
Of your guesses, you almost bought FB at 30.. luckily didn't. You then said you'd pull the trigger at low 20s. It never hit that.
I asked why low 20s was your strike point, rather than mid 20s, etc., and you couldn't articulate a reason, but wanted to quibble over the term "value". If you had been confident about that 27.50 resistance point, and bought, you'd have a 20% gain, and I'd say hey, at least he got one prediction right. But so far we have two wrong on Facebook, and 3 wrong on Spanish stocks. It's hard to take predictions seriously when they keep being wrong (but vague enough that you will try to claim them right enough).
To specifically address your questions:
In what way am I a gambler?
You are a gambler because you are guessing. You're hoping you're right, and you're trying to time investments to make money, not based on what the value of the item is (which you seem to think cannot be known), but based on other traits like "I feel like there's panic, so I should buy."
What differentiates a gambler from a speculator?
Probably not much. I won't quibble over these terms, and if you want to be called a speculator, that's fine with me.
If markets are always efficient and random, why does Buffett or Tudor-Jones or Soros kick so much ass?
They aren't always efficient or random. That being said, equating what you do to how Buffet invests is laughable. He certainly looks at value. He doesn't buy planning to sell anytime soon, his time frame is almost always decades (at a minimum). He's buy and hold.
Can stuff be undervalued? Certainly.
Or the thousands of anonymous traders who walk away with tens of millions because their "feel" for the market proved uncannily prescient?
There's many millions more who lost tons in the market. I'd say the number of traders who we don't know about (anonymous) and walked away (did not go back and speculate more and lose it all) and made tens of millions is vanishingly small. You could probably count them on one hand. Not the "thousands" you claim.