1. I don't care what these pro gamers say and forming a list like you did still doesn't mean that a immobilized target is the same thing as outright wiping a target from existence. It may be more efficient to stun the target, but why do that when you can just erase it? Do you have a Webster dictionary?
2. The problem that some people are having is that they are comparing a Paladin tree to another class tree. In this case, Fighter. Paladin is not the only class getting its trees updated and current trees aren't set in stone. Its wrong to compare a Kensi to a KOTC or monk abilities to a Paladins abilities. Its wrong to compare AP costs to other trees. It makes much more sense to improve current abities and cost that are balanced properly. You balance trees against other trees that are not balanced right and you don't make the tree better.
3. I think Holy Retribution is fine the way it is. The only problem I have with it is not knowing when a mob is down to 1k HP. If vorpal was to be replaced as an insta kill against a save, I'm fine with that too. Make it so it works against chaotic, evil and undead. Now it sounds pretty badass. Something that powerful should have a cool down. There's already enough abilities to use that take up a Turn and if they make Turns better for Paladins, I will want them.