Yeah man, that Sonic was good, but needs a balanced FS to go along with it, also a chargeable homing attack that actually targets it's opponents rather than blindly aim would be better.
The thing about MetaKnight's FS is that it required timing and for you to be close to an opponent which in the end didn't feel so rewarding because it didn't always KO unless the percentage was already high, but yeah, other Final
Smashes like Snake's could use a better suited one, (like REX) also his camping game was goid but his aerials game was horrible, overall good powerful character which I actually find ironic since Snake doesn't seem to feel "slow and heavy" in any of his games.
As for the Super Smash, yeah, having some technical moves would make it a little more appealing indeed (IMO) I guess as long as it doesn't breach the barrier of Smash and jumping the fence into Street Fighter territory which we don't really need, of course such stuff like tripping should either be removed completely or have a switch of sorts, this could essential be use during competative play (tourneys) without resorting to hacking a Wii-U, just like it's done yo Final Smashes; which is good because it's what makes Smash Smash different from other fighters.