Oh God no . . . maybe Roy, but the rest definitely need work still.
As for how to fix Lucario, I really think that it boils down to giving him a better projectile to be able to manage in the neutral at all. I don't see how switching the properties of shadow ball and aura sphere would cause any problems for either Lucario or Mewtwo, and I feel as though it'd really help balance the two out immensely.
I don't really feel like Lucario needs much help. I definitely wouldn't support this if it included getting Mewtwo's full charge kill projectile.
Lucario has a bad dash dance, which isn't great for neutral, but honestly I don't think his neutral is bad. His projectile is decent simply because it travels different speeds based on how charged up it is, which helps it not get powershielded so often (if they don't mix it up, it's fairly easy to reflect admittedly).
That said, he has some pros in neutral that no other character can boast. His down b cancels allow him to approach, be invincible, and have a hitbox out all at the same time. The invincibility doesn't last the whole time, but it means if you space it right, they can't trade with you. The opponent HAS to take a defensive action.
Also, even if Lucario doesn't have a charge, non-canceled down b is a surprisingly good approach. He has two frames of vulnerability at the end, and the move is fast enough where 7 frame grabs are not likely to intercept it on reaction. This means he can down b and keep holding down, which will ASDI down if he's hit in those two frames and he can counter. It means he can get in and be scary to attack, particularly at low percents.
Down B aside, keep in mind that his fair has sword level disjoint, is fast, and lasts a bit longer than most sword moves. Generally all his moves are fairly disjointed, which helps in neutral as well.
Lastly: his recovery and combo game are ridiculously good (if he has a charge and DI's well, he recovers for free with an invincible down b canceled attack). He can also gimp fairly early with side B. If they nerfed his down b and recovery, a projectile buff might be warranted, but even then I wouldn't give him Mewtwo's super fast fully charged kill projectile.
I'd put Lucario in the top half of the cast, but below the god characters who imo clearly need to be nerfed. I personally think some small nerf tweaks should happen to Lucario because I think his down b can be somewhat toxic, but that he's in a fairly good spot in the game balance wise. So if they did said nerf tweaks, buff tweaks elsewhere would be fine.