If you call enshrining the right to life and the protection of marriage in the constitution "big, intrusive government", I disagree, but yes, it is a good thing.
If you think spending should be cut significantly, reducing the size of government, I agree with you, and Santorum has the strongest platform of any candidate in the race to accomplish that goal.
I'm sure Santorum's regulatory platform is vastly better than what Obama has in place but I do not know the details of his proposals, though I suspect he would not be as conservative as me.
The Federal government never has had any business getting involved in marriage. This is something between people and God. If a state wants to recognize it or not it should be left up to them.
I think that a big federal government is a bad thing no mattter the policies that it espouses.