21 Put “I” in to word for nonsense and you’ll get a funny person
22 one of the clues I thought was forced. You are given “coastguard” as fodder for an anagram then asked to forget “coast”, so just an anagram of GUARD* + AT + ION (no one returning)
25 Article generally indicates grammar, so A, AN or THE. Judge is the chap on a sports pitch (a useful three letters for the setter) + OR + E (head of enquiry)