Yes, I would prefer the federal government tell everyone what they can do with those issues. I mean, look at where we're at right now. We have about 20% of the states that allow gay marriage, and out of the other 80%, a very large majority doesn't even recognize the marriages from the states that allow gay marriage. This is an unequivocal bad thing.
The churches have no say in whether or not gay marriage is legal. They have every single say whether or not to allow it in their church, and if they don't allow it, that's their business, and I support them in their right to do that, but they don't have a say on whether people can do it outside their church.
Abortion is the same way. If we have some states that allow it, and some states that don't we're just gonna find an influx of people who travel to other states specifically to get abortions, or worse, just stay in state and do it less than legally. That's the issue here. People are going to get abortions, that's a fact of nature, if we allow it, we're at least allowing a way to do it safely, without harming the person getting it. Leaving something like that up to the states would end up hurting people in the end.