You make some excellent points. At first blush I can’t really see any flaws in your argument. Let me cogitate on it and get back to you tomorrow.
For what it’s worth, I was away from the Church a long time. And its position on sex was completely baffling to me then and (to some extent) can be perplexing even now. But the more I study it, the more rational I find it, and I find that it is always me who is looking at things the wrong way.
So I can completely relate to where you are on this, and I think you have exactly the right attitude. Skeptical, but curious and intrigued all the same. :)
This has been a very nice discussion. It has reminded me of one of the reasons I admire Catholicism (even though I don't embrace it); unlike many religions, it has the ability to integrate reason along with faith and scripture.