LOL @ These suggestions.
His "utter lack of knockback at low percents" was his same problem in vBrawl, and no one complained. Why? Because combos don't truly exist, and Lucario was terrible at punishing things because his moves released slowly. Now, he can combo very well from a grab.
Let's consider something, though. Lucario can combo about 12 hits with no problem at 0 percent. I think it's wonderful that this massive, 12 hit combo does about 30 damage, if that. You can look at Ganondorf, who can do about 110% damage with 5 hits, and no one complains about that. Yes, Ganondorf has his weaknesses, but we're just talking about combo material and damage output. What about Ness, who can use F-air to any of his aerial moves as a combo, including the D-air which has more knockback at 0 than it did in Smash 64, and is unable to be meteor-canceled? I hope you're complaining about other characters as well while you are complaining about Lucario's brokenness.
Upthrow is a bit ridiculous, but the aura is what makes that so. It's always had that form of knockback in vBrawl. Lucario can't kill with an upthrow --> U-air combo until his opponent is at about 190% (while he is at 0) or until about 125% (while he is at 100%). In comparison to a game such as Melee, where you have characters with stupid grab --> death combos (Ganondorf, Fox, Falcon, Pikachu) at high percents, it's really not that ridiculous. Most characters, from what I've seen, have a reliable grab-to-kill move combo at higher percents, I don't see why Lucario can't have one either.
Let's not forget about Bowser's UpThrow knockback. If you look through GameGalaxyBrawl's videos on youtube, you could find "Rayku vs. ZeonStar 2, Lucario vs. Bowser" on Halberd, and watch me lose my last stock, helpless to do anything.
upB is the only thing Lucario got in Brawl+ that makes him any different than in vBrawl. Go ahead and take it away, I don't really mind. However, a really nice change would be so that there is no lag after landing, so he can't be killed by punishing him like a G (kind of like what you can do to Sheik in Melee). I would very much like a small hitbox on Lucario's extremespeed (I mean, it's more powerful than Quick Attack, and Pikachu gets a hitbox. Real talk, baby), and taking away the free fall. That'd be awesome.
@CloneHat: -broken-? Metaknight's recovery is BROKEN, sir. Lucario is very far from having a broken recovery "before auto-snap," unless you're referring to his lack of freefall afterwards, in which case Lucario's recovery is simply "very good," and not broken. In Lucario matchup discussions on other character boards that I have seen, I have seen Lucario players defend his recovery as not being bad, while ignorant people say that Lucario has one of the worst recoveries in the game.
@KOKingPin: Chad went Lucario in the last match because he didn't think Falcon would work, and Lucario was the only other character he knew how to play that he felt stood a chance. At least, that's what he said to me.
In General about the planking, which apparently isn't anything new (according to what that guy posted earlier when I said something about it, you could do that in vBrawl and it was "just as bad." Wonder why no Lucarios ever did it in vBrawl to win. Oh yeah, because it was gimpable). It's not anything to do with Lucario's fault. The quick startup on upB was a random change that was thought to be good, and it keeps its invincibility because of a general rule that Brawl+ has (the instant let-go-of-ledge property). If I ever saw a Lucario use that in order to win, I would be ashamed.
Brawl+ still needs a legdge-grap rule to be enforced.