A bob is slang for a British shilling. Two-bob means two shillings. There are twelve shillings in a pound. "Two bob" typically precedes an insult where you are essentially saying the person is worthless.

The phenomenon of having to come out as bisexual to the same person/people repeatedly because they assumed or hoped that your sexuality was a "phase." Refers less to the holiday and more to the 1993 Bill Murray comedy film in which the main character experiences the same day over and over.

An insult, basically a polite way of calling a person a cunt. Referred to in The Libertines song "What a Waster".
To give it a continental feel can be translated in German to 'Zwei Mark'.

when someone is not worth a wank

Class bloke with a great attitude towards friends and family.