I've worked out the (unnecessarily difficult) clues to 7 and 24 now, although removal of the rogue bar means that 24 solves itself - if you've filled in the perimeter.
So, 7 is NEWIE. The extra letter is O, not W. I take 'red' to mean to 'put in order', so it's an anagram of 'wine' + 'left wing to excessive' (the letter E!).
And 24 can only be made to work if you take 'means' to signify 'the mean - aka middle - letter' of 'using' (I) and 'tasty' (S), which are then 'bats' (extra letter I) to trap A. I think the familiar anagrind 'bats' crosses the borderline into unfair territory here - how can you make an anagram out of two letters? But he does it again in cell block 5, using another anagrind for two letters. In the case of SAI, I can't see how such a bizarre clue is justified.