I finally re-watched this film, and I have to say my intial reaction of thinking it one of the lesser of Bronson's 80's work has changed. But perhaps that is because I no longer have so much of a running list.
I will say you are about 99% correct ... it is a frustrating film. It should and could have been better. Bronson's eyes as he watched the documentary tape in his house demands this film to be better (so does, for the record Mr. Ferer's voice).
As with so many other almost-good films, this was an opportunity missed. But unlike so many of those good films, this one is rewatchable (okay, so maybe if your human, you should fast-forward the torture sequence in the begining).
I used to hold onto my anger after watching a film that had so much potential, but now I try to let it go more. But based on the chance I could take a timemachince back to 1984 these are some of the things I would have done differently:
1. The car bomb? Illogical sequence, even IF the doctor was going to get in the car, he's not the one who would start it and most likely wouldn't get in the car until it WAS started. At best he COULD HAVE been hit by the explosion, but that's not a sure-kill by any means. I suppose the filmmakers wanted to show that Holland was the only one good enough to kill the doctor ... but to do that perhaps they should have allowed the doctor's men to capture and kill a few other "lesser" killers.
2. The wife. There have been better actresses. Might I suggest Lauren Bacall. She would certainly have the screen presence and acting chops to show us the transition to loving Bronson (still it would have been better if she never did ... making for more complicated interactions).
3. The doctor. I am tempted to say Burt Lancaster in this role might have proven to be amazing, but the original cast really had the implied incest thing down-pat.
4. This goes back to point 1, but lets us see the henchmen do more, or be more effective ... more of an opponent to Holland.
5. An over-all re-write.