You could call people like that "turncoats" or "renegades." You could describe them as "dissident."

No single verb I know quite captures what you've described, but try "abandon," "desert," "betray," "defect," or "dissent."

Words that fit into the blanks in your sentences are "resents," "scorns," "rejects," and "disdains."

When someone is different from their origins, especially when a child is different from his or her parents, people say, "The apple has fallen far from the tree." There are lots of variations on the phrase "too good for," and in this context someone might contemptuously say, "They think they're too good for us now." When people mock others for qualities they themselves exhibit, like the partier who looks down on other partiers for partying, you might say, "Look at the pot calling the kettle black."

Apophasis is the term.

OED defines the term by quoting John Smith's The Mysterie of Rhetorique Unvail'd (1657):

a kind of Irony, whereby we deny that we say or doe that which we especially say or doe.

Here is the definition from grammar.about.com:

A rhetorical term for the mention of something in disclaiming intention of mentioning it--or pretending to deny what is really affirmed. Adjective: apophatic or apophantic. Similar to paralepsis and praeteritio.

_{Wikipedia mentions that it is a rhetorical relative of irony and lists the following equivalents:}

_{Also called paralipsis (παράλειψις) – also spelled paraleipsis or paralepsis –, or occupatio, and known also as praeteritio, preterition, cataphasis (κατάφασις), antiphrasis (ἀντίφρασις), or parasiopesis (παρασιώπησις).}