as far as i know there a rea fair few people getting the tune done by auz in melb when he goes down.
as for insurance, im not telling my insurer, theyd just use it as another reason to increase premiums.
also, there are so many different files, i really doubt your insurer would have a copy of each stock file, therefore theyd have buckleys chance of discovering a tune.
itd have to be a pretty fine toothed comb!