Proving to be tough.
Either the clue has an extra letter to be removed or answer has to be modified before entry so
answer length could be different than given.
5a.Top auditor to resist female paymaster (6)
40a. What’s naturally instrumental in faithfully capturing term poet misused? (11, 2 words)
1d. Tends to leave campaign funds in vaults (6)
12d. What causes resistance borne by violinists essentially (5)
33d. They are involved in rigging up network configuration to protect connection (5)
5 BUKSHI (sounds like 'buck she') 'to[p]' 'p' is extra.
40 TRUMPET TREE (anag + extra 'o' 'p[o]et').
1d extra 't' '[t]ends' to leave (w)AR CHES(t)
Would you prefer hints for the rest, hankir?
...12d is &lit - 1 letter for 'resistance' + 2 letters for 'bo[r]ne' + the centre of the penultimate word.
33 is thematically altered on entry - for the initial answer (8 letters) you need to reverse a common 4 letter word for 'network configuration' (it more generally features in a rating system - hotels, restaurants etc) around a 4 letter word for a (phone, maybe?) 'connection' - def is rigging on a ship.