Hi Roof,
4a - definition is "error" and it's a 3 letter word meaning "I hate that" repeated.
17a - 2 letter "popular" then 5 letter "ceasefire" goes around a reversed/'from the right' 2 letter "party"
22a - 2 letter "Roman figure" and 4 letter "leader" - if you convert the the numeral to English and put it before "pack" you get "muscly"
2d - 6 letter "fluff" as in 'mess up' minus single letter "unspecified quantity"
16,17 - 2,2,2 was a 24,9 winner (I think) an entry anyway, followed by "end not beginning"