> Christianity considers any sexual activity other than heterosexual sex for procreation within marriage to be sinful,Mostly true, except the "for procreation only" part. That's specific to Cathlicism.
Protestant doctrine tends to be "anything goes, so long as it's in marriage", with the implication that marriage is heterosexual.
> and female sexuality to be inherently corrupting because "it was Eve who tempted Adam in the Garden of Eden."
I don't know of any non-sectarian modern Christian group that think like this. I don't think it was even current thought at the time of the Reformation.
> The Christian dogma
You are, once again, talking about Catholicism. No other denomination calls their teaching "dogma", because only Catholicism claims to be infallible. And for that reason, any serious error in their dogma is nearly impossible to excuse without some serious mental gymnastics. Other denominations can go to the Bible and point to a passage showing some attitude was wrong, change their doctrine and move on. But not Catholicism.
I also heard these things in sociology class at school, but they are outdated and partially incorrect. And it's a very anachronistic interpretation of history.
> That isn't "sex positive" in any commonly understood sense of the term.
No indeed. Modern Christians aren't either. But that's not what the GP was referring to. What you got was women actually being consulted on who they should marry, getting basic human rights and so on. Which, at the time of the first century A.C., was rather revolutionary. A lot of these were weakened over time by Catholic (and also some Protestant) culture, but treating people like people is very much a big message in the Bible.
Another big message in the Bible is restraint, so of course Christianity can never be fully "sex positive" in the modern anything-goes sense of the term.