DDD's infinites, IC's infinites, Yoshi character specific infinites, Marth character specific infinites, dtilt against walls, CG against walls... basically if you know how to do one, you should have a good idea that it is an infinite and is not permitted. I'll gather a list but I think most of them should be known already. Regarding the doubles chain grab, only do it when it is escapable. Once it is eternally inescapbale and therefore an infinite, it's banned.
Chain grabs are still allowed because they are considered to be part of the character's moves/attributes. Infinites however, are unintended, inescapable loops in the game that give free kills to certain characters or match ups rather than large advantages that require skill to counter. I know that most chain grabs probably weren't intended either, but they are not so significant that they can single-handedly determine the match.
This is plain out ridiculous...
Non of these "infinites" are even ban worthy (maybe the IC chainthrow is broken but even that is arbitrary simply because it is arguably difficult to get the grab and that it's escapable at early percents). Not to mention, dtilts/grabs against walls are entirely situational since
not all stages have walls. Character specific infinites should also not be banned because they are.. character specific. This game allows for counterpicks for situations similar to this. If your going to select a character like DK vs DDD, then expect a very difficult match. And if you have no secondaries to make up for DK's weaknesses vs certain match ups then tough luck. Pick up a secondary. That's how competitive smash works.
What you should ban is CG stalling simply because that is a form of stalling. That's really about it.
Also, I find your notion of trying to create a balanced and fair game very naive. I mean, how ignorant are you? Do you fail to realize that some characters have natural advantages over other characters to begin with without the use of infinites? Do you fail to realize that some of these "infinites" would help level the playing field for certain characters in match ups they would normally fair poorly against? Let's take IC as an example. Do you understand how difficult it is for IC's to get a grab on MK? It's just down right hard. And the fact that MK already has the clear advantage doesn't make things any easier. There are times when Nana would be on the other side of the screen once the IC gets the grab and at that point, the grab won't mean much at all. This match up is practically as hard as IC vs Peach in Melee.
Mio, you play 3S right? I'm going to assume you know a good deal about that game. You know what happens when a Makoto lands
one Karakusa grab on Akuma? Instant stun, which could lead to an easy 100% combo.
Mio, don't follow through with banning all these infinites please. It's only going to make you look like a Brawl noob.