I also loved the suggestion that bringing a character back should be more than just a spell; it should require a quest, or the magic should be inherently dangerous and have added drama/story to it. In my current setting, it’s illegal without the approval of a council of churches, who rarely agree enough to permit it.
The only time I’ve pulled punches was in the final game sessions of a campaign that had gone on for over a year. I knew that in the climactic final games, unless the story called for an epic/tragic death (it did not), I was not going to let the party die. But for me it had come to a point where it was now just a story to finish off, and less of a “game”.
Oh, also, great points about playing monsters consistently. Players really enjoy seeing tactics that make sense for monsters!