"Gay" marriage questions

So, when the definition of marriage is eradicated and homosexuals can "marry" with the endorsement of the government:

1.  Will it become illegal for a pastor to proclaim what the Bible states about the act, that it is sin (like adultery, beastiality, incest)?

2.  Will Christian organizations (and for that matter, Muslim organizations) be permitted to not hire those who do not hold to orthodoxy?

3.  What about non-sectarian businesses?  I really can't imagine this anymore, but if a corporation or mom-and-pop joint felt that such conduct stood contrary to their corporate image, would they be free to not hire those they felt to be morally "suspect?"

4.  Many counter that this will not open Pandora's Box to other and alternative marriages (why can't Bob marry his puppy?), but can someone explain to me that if marriage is no longer between a man and a woman (the parts seem to fit, btw), why it can't be between men (plural) and women (plural) or men and trees or men and men and women? And what's so wrong with incest? Or children?  Please don't recoil at such a question.  Many never imagined the homosexual marriage thing would be embraced with such favor or fervor.

Our nation saw fit to reward those who chose to marry (man and woman) in days of yore for very specific reasons.  Little did they foresee the ramifications that so innocuous a governmental endorsement would have upon our nation.