I believe that the Founding Fathers wanted to prevent a state-religion from starting, such as the Church of England where the head of the church is the reigning King or Queen. As I recall, for anyone to move through the political and social ranks, the person had to belong to the Church of England. The admendment says nothing about not voting as your moral/religious code dictates. This is true if your are a citizen or a member of Congress. So, yes, there is seperation of Church and State.
Yes, the principles the United States was founded on have their roots in the Christian faith. It's a system that works whether you use it in a religious or secular setting.
THe governement has a responsibility to look out for the general welfare. To quote the preamble, "We the people of the United States, in order to form a more perfect union, establish justice, insure domestic tranquility, provide for the common defense, promote the general welfare, and secure the blessings of liberty to ourselves and our posterity, do ordain and establish this Constitution for the United States of America."
This means that any activity that is detrimental to the General Welfare will be regulated and stopped. Drug abuse falls under this guise. How many roberies have their roots in obtaining money for narcotics? How many deaths of innocent bystanders are caused by drug abuse? This and other such activites are a threat to the general welfare.
Abortion. There is no easy answer to this. A friend suggested years ago that if the embryo was viable outside the womb, an abortin would not be allowed. Unfortunately, that was before cloining became reality. Now, soon after fertilization is the blastula (think hollow ball of cells) viable outside the womb? We have a responsibility to prevent unwanted pregnancies. When birth control is actively taught and made available, the number and desire for abortions will go down.
Should politicians be allowed to "Bible thump" First amendment says they can. If you don't like those in office, vote them out.
Chaunte