Well, Isis_ - from the list of books that you have read it seems you appreciate the more biographical/historical/documentary aspects of writing about Dylan, so some other books you might like to consider are -
Million Dollar Bash - Sid Griffin; about the Basement Tapes.
The Songs He Didn't Write - Derek Barker; about the songs Bob has covered throughout his career.
Just Like The Night - C P Lee; about The Free Trade Hall concert 1966.
On The Road With Bob Dylan - Larry "Ratso" Sloman; about the Rolling Thunder tour.
The Rolling Thunder Logbook - Sam Shepherd; also about the Rolling Thunder tour (and in my opinion the better book, but that's a whole other can of worms).
Razor's Edge - Andrew Muir; a story of following Bob on the NET, a great and interesting read, but here we're beginning to edge over into critical analysis, so -
Like A Rolling Stone - Greil Marcus; a study of the recording of the song (with some minor factual inaccuracies) and a consideration of its wider context. Contains Marcus' best writing on Bob imo.
Revolution in the Air & Still On The Road - Clinton Heylin; full of information about the recording of the songs and lots of opinions too, views may vary.
Bob Dylan in America - Sam Wilentz; a very well written attempt to place Dylan in the historical continuum of American music.
Performing Artist, Vols 1,2&3 - Paul Williams; great.
Song and Dance Man - Michael Gray; despite the carping by some, great.
Alias Bob Dylan Revisited - Stephen Scobie; a poet's view.
Dylan's Vision of Sin - Christopher Ricks; a literary critic's view (and a much better book than you may have been led to believe).
Bob Dylan: The Never Ending Star - Lee Marshall; a sociologist's view.
.... I've just realised that I could go on for a pretty long time so I'll stop now ....
Except to say - I notice you don't say you've read Tarantula - there are any number of good reasons for reading it, one good reason though is that it's fun - of course once having read it you can form you own opinions about Bob's first book.
This list is excellent! Great choices. Only two I haven't read--Marcus' Like a Rolling Stone book (it's at the corner used book shop--I almost grabbed it yesterday, but I didn't really dig his Invisible Republic book, so I hesitated and set it back down). And Alias--I haven't even heard of that one, I'll hunt it down. The only book on this list I just couldn't get into was Visions of Sin, which I so desperately wanted to devour, because the idea of it really compels me. But I feel like an idiot reading it--I just can't follow the writing--it makes my brain hurt--perhaps Ricks is working above my capacities.