One of the best games of 8-ball I ever played took almost an hour. Nineteen safeties! And believe it or not we got an ovation from the crowd!
A time limit on a game wouldn't work very well, but a time limit on each shot does work pretty well. No shot requires four minutes! A 30 second time clock, with a 30 second extension for unusual situations is plenty of time.
I once played a 3 time champion in the APA 8 ball singles. The winner got 5th place and like an extra $1000 prize money. We play a race to 5. I barely won 5-4 and it took over 2 hours. We both play a very determined, strategic game. Lots of safes back and forth. It was really an excellent match. I am a slow player. My opponent was no speed demon either. But after the match, we both talked about what a great match it was and how much we enjoyed playing. We were grinding like crazy, giving nothing away, and it was SO FUN! One of the most enjoyable 8 ball matches I have ever played. I am pretty sure many shots of ours took over a minute. At one point I played a pretty tight safe, he looked and measured for a long time, and kicked 2 rails and MADE the 8 ball!! It was awesome! It was totally worth the few extra seconds he took to do it.
I really don't know why people can't enjoy the game itself a little more, learn to deal with their own anxiety a little better, and just relax about the time limits. I mean it isn't like we were laboring over straight in stop shots. Every shot in a winner break bar table 8 ball race to 5 could be the match. Its very tough, and it can take some time. Demanding a fast 8 ball match is not unlike demanding a fast 1 pocket match. Rotation games on the other hand require far less thought. 9 and 10 ball are simple games. I would agree that 30 seconds to decide what shot is way more than enough in most cases.
Either way, I wish people could learn to compose themselves and just chill a bit more when playing. Why does it need to be a race? I don't care *when* my turn comes, I just hope it comes. If my opponent is slow, then I know I can take the time I need. What most people that play fast fail to realize is that for a slow player, it can be intimidating to watch someone shoot the right shots and shoot well very quickly. The fast player should learn to feel good about this "advantage", rather than whine about the pace of their opponent. Lot of anxiety out there.
Anyway, my $0.02