26 is a German prefix (referred to earlier in one of the threads) inside fragile material (what windows are made of!) Followed by A-list less is. I would never have got this without the earlier hint.
Re 23, Careful is 6 letter word. Warning as in golf, carol as in sing, around a word meaning improbable, often applied to a story. Definition the last two words
Thanks so much, quisling. That's the very word I had, simply because I had the anagram fodder for it when I'd entered everything else. I'm duly chastened.