Mack - I found this v hard too - but perseverance finally got me there. I'll try to give hints without giving too much away.
2d - the adjustment is in the entered answer. It's a 'sounds like' clue for someone who applies.
3d - the adjustment is in the clue. You need 5 + 1 for the wordplay; all backwards.
4d - adjustment in the entered answer. Definition at the end. Wordplay is 6-letter word missing a letter.
40a - I thought this clue was very clever and it's hard to give a hint without giving it away. The adjustment is in the clue, at the beginning.