sounds interesting. and tough to write. at once it dredges up recollections of 'chaplin' and 'queen of the damned. it's easier to see why those movies were made. i mean, charlie chaplin, a legend, and seemingly a sure-fire hit based on popular novels written by another legendary person, anne rice.
i'd like to see the story, myself. along with the obvious drawbacks (or not so obvious, i guess) is trying to make crowley an endearing character, or at least one audiences will embrace. it may be difficult to show him in a good light. is that why you added the reporter, to counter-balance crowley's profane character? if so, i'm not suggesting that's poor writing, but in itself is fairly obvious and, personally, i'd handle with kid gloves as some characters can be 'mary sues' here. i otherwise love it when characters like this meet: i've written stuff like that, albeit generally in a horror genre and involving ghosts, lol. even then, it's not bad by any means, i don't want to mislead you, just that it tends to happen when your character is virtually a villian at least to some degree. if i recall, 'quills' was similar in that respect, too, the kate winslow character acting as the much needed relief from the MC's unsanity.
telling the tale from different points of view reminds me of 'immortal beloved,' the flick about beethoven. oh, don't get me wrong, i'm not implying yours isn't an original script in how the story is told, just that those are some movies that on the surface have the same storytelling methods you suggest and you might want to check 'em out if you haven't seen them already. to be honest, these movies tend to be a chore to watch, but if you're going to write in that vein, it's good to see where those movies went wrong and what worked, eh?
i am a little confused when you say pamela meets him at the climax, then say there's a seduction, which implies there's a lot more story to be told after the climax.
i really like the idea of crowley's story being told from different perspectives. the problem there, i think, might be getting permission from the families of all those people, all of whom will want to be paid, i'm sure. i don't know if it would help its saleability, but fictionalizing those characters may be something to consider? beyond that, there's some different arrangement methods you could use if you felt the need to explore them, which i'm sure you realize. i think it's good and bad to ignore an interview with crowley: it sounds like a fun challenge by including him in the present.
i don't know why some people think every historic person deserves their own movie. certainly, 'immortal beloved' had a brilliant premise, but following the supposedly historic record of the man i don't think served the movie as well as had it been fictionalized and freeing the story up to be, you know, entertaining. same thing with e. a. poe: brilliant writer, a morbid life story, sure, but is that enough to put people in a theatre? what' funny is when they abandon some historical veracity and *still* make it boring.
it sucks to say, but i'm afraid the audience is pretty limited for most of these stories. that's why i think crowley should be made, but made with a keen eye towards entertaining along with insight to the character, even if that insight is a bit guessed at for storytelling purposes. anyone ever see 'pollock'? me, neither. another bio that bit the dust.
these bios seem tough to make work unless you just say the hell with it and go the 'young guns' route (which actually contained quite a bit of historical accuracy in terms of the events that took place, even if those events were tarted up a bit, i.e. a lot). here, you're trying to tell fictional historically accurate bio. ah... hell, yeah, sounds good to me.
don't write yourself into a corner and it should be a lot of fun to do. as you expressed the summary here, the climax is too vague to comment on really.
did ever crowley say 'do what thou wilt, so mete it be'? that's the quote i've used many a time.
