Total Agreement
It depends. You have to play what the table/balls give you. For me, it depends on where the cue ball is in relation to the stack. If I have an angle to go straight into the stack and freeze it there, that's what I will do and in my opinion is always preferable because if you can freeze the cueball and open up some balls, it makes it that much tougher for your opponent to not leave you a shot. If there's only a glancing angle to the stack, I'll either try to leave the cue ball froze to the rail behind the stack or froze down table on the head rail. Of course there's always the chance of leaving a deal ball, so if you're going to thin the stack, thin it as thinly as possible.
Edit: Also, Earl and Johnny thinning the stack more often means they were trying to leave each other down table as much as possible. A length of the table shot on 3 7/8" pockets certainly isn't a gimmie.
I couldn't agree more. Taking what the table and balls give you from where the CB is resting in relation to the pile each shot is key - with freezing the CB to the stack and kicking out one or a few balls is most desirable.
As for your Edit, I watched the safety play between Earl and Johnny and that is exactly what they did. Freeze the CB to the stack if possible, then thinning a ball when freezing it wasn't possible. The rack eventually became somewhat loosened up and one of them elected to go uptable with the CB. They each then played several successive extremely thin shots on the stack and put whitey back up table. They did this without separating balls and without creating dead balls. Their ability to thin balls so slightly from such a great distance was most impressive - particularly for how old their eyes are. Doing it once can be accidental and make you look like a champ, but they both did it several times making it obvious that what they were doing was no accident. Some of the best safety play I've seen in a long time.
Two other things worth mentioning - the crowd seemed knowledgeable enough during the safety play to recognize what both players were doing was high quality and something very special to witness live, offering loud applause as each successive safety was executed with near perfection. Although not at the match, I got the feeling that the crowd was electrified and hanging on each safety to see who was going to make the first mistake and lose the battle. The second thing I noticed was that the crowd reacted equally to both players. Their applause wasn't louder for JA and muted for Earl.
I may be wrong, but it was when Earl attempted to make a difficult combination out of the pile from uptable after this safety play that one member of the audience applauded his miss. To me it was in poor taste to openly applaud his failure after the incredible safety battle they both just put on and Earl had a few words to say to him. That was the "I just sh!t all over myself and you cheer?" comment, or words to that effect. To me, the guy was a bum for doing that. Out of the hundreds, maybe thousands of matches I've watched live, on DVD and streaming, I've never seen a member of the audience deliberately cheer when a player missed a shot because of the miss. A delayed cheer for JA as he approached the table would have been understandable, but it was obvious the guy was applauding the miss rather than in support of JA getting back to the table.
Ron F