Pastors could do the civil ceremony in the church office prior to the wedding in the sanctuary. If we really believe in the separation of church and state and really believe that the Christian wedding ceremony is a covenant in which God participates, then we have to help people understand both concepts without rejecting or demeaning people of other faiths or none. As the world becomes increasingly secular, we Christians need to give a clear message to the world about how we are different. This is one way we could do so without appearing judgmental of others. We do not need new General Conference legislation.
Many local congregations have specific policies about weddings.
Pastors can accept or decline nonmember requests. They could still reach out to those who may not have a congregational home by offering to do the civil ceremony. At the moment, most states do not allow civil marriages for same-sex couples. However, slowly but surely, that is going to change. The Church has survived in environments much more hostile than the secularity of today.