Good points, Ken. Of course the Founders' faith influenced the Declaration and the Constitution. That doesn't mean they intended to establish a state religion, official or unofficial.
And I think your comment about "freedom from religion" misses my point. Our government should be neutral when it comes to different religious faiths, especially in America's official statement of patriotism. While I don't think "under God" in the Pledge causes tangible harm to people (despite Newdow's boneheaded claims), I think it does go against the principle of freedom of religion.