I was surprised by the answer you gave regarding the florist. I’m a little confused. If a same sex couple wanted you to perform their wedding ceremony, would you? If a heterosexual couple came to you with the same request yet you knew one of them was a habitual liar, would you perform the ceremony? I understand that there really aren’t degrees of sin. But it just seems wrong to me to help someone celebrate their sin, which is what anyone who offers a service for the wedding, or attends a wedding is doing.
In my opinion there’s a big difference between being a vendor and being an officiant. A vendor is simply providing goods and services for a fee, and usually does not attend the ceremony. And as I said, there are no Biblical restrictions against doing business with non-believers and sinners.
But a pastor is God’s representative, in effect putting God’s seal of approval on the union. I believe pastors should only agree to officiate at a marriage of two believers, one man and one woman, with whom they are well acquainted.