(2) To American Mudcatters: has the original meaning of 'overly pious' disappreared so completely that it is acceptable that this meaning is not even mentioned in a dictionary?

Wolfgang, in my experience in the western US, the word bigot in America came into common use during the Civil Rights movement, when it generally was applied to someone who was prejudiced against African Americans. It has come to mean a person who is fanatically prejudiced against non-whites, non-Christians, ethnic groups. I looked it up in the Webster's New World Thesaurus (1990) next to my keyboard and found "red-neck" as one of the synonyms. Redneck, as defined in the online dictionary is: Offensive Slang 1.Used as a disparaging term for a member of the white rural laboring class, especially in the southern United States. 2.A white person regarded as having a provincial, conservative, often bigoted attitude.

My paperback Webster's New World Dictionary (1988) defines bigot this way:
"One who holds blindly and intolerantly to a particular creed, opinion, etc."

The word bigot was used so much during the Civil Rights movement to describe the resistance to the end of segregation that Americans became used to applying it to people who are racist.

More synonyms in the thesaurus are:
dogmatist
fanatic
opinionated person
partisan
enthusiast
extremist
diehard
crank (see radical)

Alice