Now now, Simna's suggestions aren't horrible. They just make him a one trick pony, centralized around a very versatile projectile (go watch Simna's combo vid for versatility proof). Which would make me have no fun playing Ness, and I'd probably start maining Lucas or Sonic again.
Point being, his suggestions would work in making Ness good, albeit bland for me.
I'm honestly going to say all he needs to be awesome are some work on his throws from what we have now. And seriously, someone do something about that dair sourspot. It's freakin insane.