I really wish Nintendo hadn't been so boneheaded about patching Wii games post-release.
There were a lot of small changes they could have made to make the overall experience better. I'm not saying they needed to patch it into Brawl+ or P:M, but I think the amount of broken gameplay mechanics in Brawl is unacceptable for a AAA game that released in 2008.
They said they wanted to make the game more fun for casual players, and then they go ahead and have stupid things like Ness getting infinited by grab release, standing chaingrabs, metaknight's ability to invincible plank the ledge while getting off an uair(? might be an fair). That's no fun for anyone..
The Wii can't do any patching at all.. for games it wasn't programmed to be possible on the console. Why do you think the Skyward Sword glitch that could ruin your save file didn't get patched? Or for that matter, the Twilight Princess one? Nintendo can't patch games specifically. It was more ignorance on their part to not allow an OS level of being able to patch the game.
It's why Brawl's stage builder exploit can never be patched out. It'll be interesting to see how the Wii U handles those games, whether or not the exploits will still work to load Homebrew.
But that's off track from what I
wanted to say. A lot of your complaints there have more to do with specific gameplay mechanics
I doubt Nintendo would change. Removing any and all chaingrabs requires Nintendo to put back in the ability to DI during non-tumble (the low % stun state). Of course, they could just up the knockback on the throws that are problems, but that inherently makes them
worse in a game where following up from a throw is
already impossible. Grab release stuff wouldn't be too hard to fix, I guess. And the ledge stuff... uh, yeah, I doubt Sakurai would touch that.
No amount of patching could really save Brawl IMO.