Froggie, I think he meant Torah is open to all Jews. Yes, we have a mesorah, but that doesn’t limit who can learn Torah. What about an orphan? Does he miss out because he may not have a father? A baal teshuvah, whose father doesn’t want him to become frum?
For the question of girls learning Gemara, it’s not so simple. I once posted the name of an article which went through the different views on it. All agree that women aren’t obligated to learn Torah, but many are of the opinion that a woman may learn Gemara if she wants to.
As far as our traditions being 3,000 years old, and not having changed – that is completely incorrect. Chassidus is only a few hundred years old, and it represented a radical shift in beliefs. The impact it had on the frum world as a whole was huge, and it still continues today. There were other movements that came up, but I don’t think any of them had the impact of chassidus.
Another thing within the last 3,000 years is the writing down of Torah she’baal peh. That was a huge change. More recently (after WW2) is the rise of the kollel movement, another thing which had never existed before.
We’ve had many changes to our values, but most of the core has remained steady.