I believe abortion is murder. And we have no general federal law against murder. It's left up to the states. So it follows that abortion should be legal/illegal precisely to the extent that each state determines.
Personally I find homosexuality rather distasteful. And I don't think that my tax money should be spent to encourage it. But I also think that by FAR the biggest threat to family in America is heterosexual promiscuity and easy divorce - anyone who turns a blind eye to those problems while railing about the "gay agenda" is disingenous at best.
What does upset me is the idea that these two issues you mentioned are "core" to conservatism, while others (such as freedom of speech and constraining the growth of government) are not. President Bush's signing of CFR was a far greater attack on American tradition than any "gay rights" law.
That's nuts.