Mistrust of cultures and subcultures: Alternatives to xenophobia?

There's a good argument, I think, to be made for "tribalism." This isn't exactly the traditional definition of the word; I'm not sure where Google gets its definitions, but it says:

the state or fact of being organized in a tribe or tribes.

• derogatory

  the behavior and attitudes that stem from strong loyalty to one's own tribe or social group.

It' s that secondary "derogatory" meaning of the word that applies here. Merriam-Webster gives a similar pair, but its first definition is much closer to our needs than Google's first definition.

1 : tribal consciousness and loyalty; especially : exaltation of the tribe above other groups

2 : strong in-group loyalty

Particularly with regard to politics (which is appropriate since all three of the specific examples in your first point are political issues), "tribalism" refers to precisely the generic ingroup-vs-outgroup conflict you're looking for. As an example, this excellent essay uses the word "tribalism" this way:

But if we want to look at people’s psychology and motivations, partyism and the particular variant of tribalism that it represents are going to be fertile ground.

Note the classification of "partyism" as a "variant of tribalism".

I think parochialism comes close to what you are referring to:

• a parochial character, spirit, or tendency; excessive narrowness of interests or view; provincialism.

Another option: Insular

6. narrow-minded or illiberal; provincial: insular attitudes toward foreigners.

Stressing the distance between cultures would be ethnocentric.

Evaluating other cultures according to preconceptions originating in the standards and customs of one’s own culture.

The first generation of western historians to address the western environment as an agent in shaping the region reflected the ethnocentric preconceptions of their time.

Reference:
http://www.oxforddictionaries.com/definition/english/ethnocentric