Said in response to someone saying thanks. Comes from a Joke where David Hasslehoff asks a Clerk to change his name to the Hoff... when the Clerk said Sure, No Hassle. Now instead of saying "No Hassle" people just say Hoff.
Old-fashioned term for dating, could mean anything from holding hands to a sweaty shag in a haystack. Generally used by people who still call a radio a wireless.