[Demimonde]

Actually, from what I have read I believe that most of the rumors about Glenn Quinn leaving the show because of a lack of professionalism are just rumors. Most of them surfaced only after his death in 2002 from drug overdose and have more to do with fans making guesses as to why he left. From what I understand he was on good terms with cast and crew and conducted himself as a professional. I have never seen a single account of him behaving badly, with any kind of particulars or detail, or with any kind of corroboration from someone who would know first hand.

Whedon is on the record that starting with Buffy he wanted to have someone presented as the main cast die in the first couple episodes to keep the audience on their toes. The character Jesse was introduced as one of the main high school crew only to die in the second episode. Whedon wanted to have him in the title sequence as a major member of the cast for those episodes, but expenses kept him from doing it. He relates that in the audio commentary for the first season DVD.

I think he wanted to do something similar in Angel with Doyle's character. I think the main purpose for Doyle's existence was as a vehicle for Cordelia to get the visions and have a real place on the show other than official screamer. Creating some silly thing that would give her the powers in the first episode would have been hokey. The Doyle storyline gave it more emotional impact and cemented Whedon's reputation as a cast killing director with whom no character is safe.