No, Father Karras did not commit suicide at the end of THE EXORCIST; he performed an act of martyrdom in order to save Reagen Teresa MacNeil. There’s a big difference.
Even if Karras had committed a mortal sin (suicide or any other), he would not have been damned at the end of the film, as he makes a final (albeit silent) confession before dying.
As for subliminal messages, Video Watchdog magazine did a good article on this (sorry, can’t remember the issue). While pointing out the subliminals that actually are in the film, they also dissed an earlier article written by the guy that did that “Subliminal Seduction” book. Seems he had tried to identify the subliminals in the days before home videotape, laserdisc, and DVD; needless to say, without frame-by-frame analysis, he ended up way off the mark.
By the way, I doubt the subliminals had much to do with the stories of people fainting in theatres. Remember, THE EXORCIST was released in the days before wide national releases opened films on 2000 screens the first weekend. The film played in only 60 theatres for several months; if people wanted to go, they had to drive downtown and stand in line for hours. I would be willing to bet that the advance word-of-mouth, apprehension over the subject matter, the notoriety of the book, and the long time waiting…waiting…waiting to get inside and finally see the movie–all these contributed to a mindset conducive to being scared witless. If people had been waiting out in the sun, without eating anything, they might even be light-headed to begin with, hence the potential fainting. At any rate, I doubt this happened very often (I saw the film three or four times during its intial release and never observed such an incident); probably the media exaggerated a very few incidents.
I saw the film again a few years agot at a midnight screenining in Westood, California, and I have to disagree with those today who insist that it is no longer scary or that it is camp. I think what has happened is that the audience attitude has changed. Whereas once people went to the film in anticipation of being scared, now they go in as if challenged, and put up resistance to the film. Well, almost no film can overcome a willful desire not to be entertained.
As far as boring, well, yeah, if you go in expecting special effects and violence from scene one, then you will be bored. That’s not what the film is about, despite its reputation. One of William Friedkin’s master strokes was knowing that viewers would already be worked up into a state before enterting the theatre, because the novel was so controversial and no one knew how they would film it without getting an X-rating, so he played off the expectation, toying with the audience for the first half-hour with nothing but an enigmatic prologue in Iraq and scratching noises in the attic. The much remembered projectile vomiting doesn’t occur until much later, by which time those who have come merely for cheap shocks have long since tuned out.