UnScramble this Word: t i k s r e s r?

Questions

Food: The founder of Weight Watchers?

Food: The mild stimulant "theobromine" is found in this common lip-smacker?

Geographic Tyrrivia: Name the expanse of water between New Zealand's North and South Islands?

Hitchhiker Guide: About the most massively useful thing a hitchhiker can have?

Hitchhiker Guide: British sci-fi TV show that the author of _Hitchhiker's Guide_ wrote for?