A. I don't think Santorum would force anything on America, religion wise. No way he would be even able to. Would not be a bad thing, though, to have a good man of faith in that office for a change of pace. Wouldn't worry me a bit. I'd be more interested in what he had in mind for actually running the country regarding the things that matter, security, immigration, and taxes regulation and economic wise.
B. Take your pick. Santorum or Hillary. Think about this. It's likely Obama will replace another Supreme Court Justice. But it's likely liberal for liberal. But beyond that, the conservative judges start to fall. If Hillary or another Marxist gets the White House, the constitutional republic becomes an even worse Administrative State than it is now.