No problem. Such preachers can't do it as a business in the public sector, without doing for everyone.
Wrong. Constitution. We still have one. Your law does not have the authority to force any American to violate their religious belief.
Wrong- the courts have repeatedly addressed this.
Seventh Day Adventists cannot prevent their children from receiving medical care.
Religious cults that want to sacrifice animals don't have the right to sacrifice them in violation of local laws.
And as has been pointed out- no person can deny service to a Jew just because he says it would violate his religious belief.
In states where there are laws against sexual orientation discrimination, it is the same thing.