Also remember if you want to enforce this as a regex-only kata, you absolutely can :)

6 Kyu sounds about right - complex regexes, but not really advanced regex usage. The kata doesn't get harder if people don't know regexes. ( It's not intended to be solved without regexes, given the tags. )

Random test generation looks good to me. ( Keep in mind that any edge case that is found by the random tests should be added as a fixed test. )

Final thought: if you need fully half a page of description to define "word", maybe you should use a simpler definition of it for your kata. I'm all for exact specs, but this borders on ridiculous. Or maybe plain text just isn't the best way to express your definition, and you should be looking into some form of BNF. The resulting regex seems simpler than the description.

Thanks for the feedback Dom! I thought the examples would make that clear, haha. I've updated the description with your example xD