Very slow with this one - a few of the difficult ones.
9A - In Robert Frost's "The Road not taken", the speaker is therefore this (9) I have R?????F??
3D - Poe's raven would not make the least such expression of respect (9) I have O???????E - anagram of Poe's raven ?
16D - Factional Italian history written in Spain (1, 8) I have I?L?U?I?S
17D - He wrote in Fleet Street and in a music-hall (8) I have ?A?I?S?N (Harrison ?)