Ok, for 30a think pen as in swan, it’s a homophone.
28a is another literary reference, from Barchester Towers, Mrs Slope’s rival.
14 d an odd word for shaving with ancient Greek derivation.
5d join up the first two words of the clue and look it up
22d a Biblical reference for devil, Revelations 9.11, opposite of a good fellow (as in academic)
21a anagram of odd with one musical note inserted (single letter) followed by and. An old fashioned term for accidental cause of death given to the Crown
26d remove first and last letters of a word for steal. It’s rub as in rob, bit obscure.