1. A truly even matchup determines quite possibly everything. This is not your stance, and I don't expect to reach one, so eh.
2. Being closer to true balance = more balance = better skill differentiation, would it not?
Yes and no. The game has balance among the top and high tier. Tournaments determine who is the better player, and the best players typically use high/top tiers. To an extent I do view character choice a skill. Characters have weaknesses, and some lower tier characters can exploit higher tier character's weaknesses, so they do have their uses.
My main question to you is why does full cast balance mean anything? People can just pick a new, better character to play. This point is actually valid now that MK is banned.
3. More Efficently(This definition makes more sense given the situation) -
Preforming or functioning in a better manner then the way it was before.
Define better, then tell me why it's better. Also keep in mind what I said previously, because it applies.
4. I am not saying the matchup definition will be perfect, but that given we can trust the validity of our own community, as long as it is more balanced then before, we have accomplished something.
What have we accomplished if we did this? Limiting CGs won't help ganon at all. Even if we banned ICs usage vs ganon, he'd still be the worst character in the game by a long shot. You'd need way more complicated rules to balance out the game, which leads to my point about doing more harm than good in terms of competitive.
5. In that scenario, Player X is better then Player Y who they beat. They are also worse then Player Z who they lose to.
They are also very likely all near the same skill level, or the matchups are incorrect, or they aren't playing the matchups correctly, etc.
Matchups don't determine everything, but they do determine what happens when both players play correctly, from the info we know.
I am not sure how much match-ups tell us. It seems everyday some top player is playing a match-up "wrong." I am starting to HIGHLY doubt how credible the community is for determining match-ups. I think if we were right about match-ups, dumb things wouldn't happen to good players on a very consistent basis.
6. As long as the change makes the matchup more balanced, it will accomplish something positive.
Again it is unclear if it would. Why would it do this. Your "proof" seems to be that balance = better at determining skill, but there is already balance, and picking a character is a skill in the game.
Removing the grab release from the Marth / Lucas matchup will most certainly do this, and you know this right?
Yes, so marth counters them. If you play a character Lucas beats, you can counter marth. That is a skill. Playing multiple characters is a skill. It's unfortunate for the lucas main that DK and marth mains will always beat them, but other people who don't main them can use them as a resource. By getting rid of GR infinites, we're limiting the need for picking up new characters, which is a step in the wrong direction in my opinion.