I like the ideas for the B moves on your moveset, however I don't really agree with using the spoon as a weapon. It's more of a manga thing, and should stay there where it belongs imo, as it holds little significance.
Besides, I kinda like Mewtwo's Melee Smashes. Make his FSmash like Lucario's in Brawl but with more power, but keep the Melee sweetspot and make it larger.
Also, I'd want to make him more heavy weighted. I said Samus' weight before, but that'd likely push it. But Yoshi's weight, or a little lighter would be perfect.
I also thought of this idea before as his Down B. Make it something like Meditate or something similar in name. Kind of based of his Dex entry being something like that he meditates everytime to focus himself to battle at full potential. Could kind of work like an overall stat buffing move.
Mewtwo would use it, and the longer you hold down B, the stronger his stats become. That'd mean, more knockback, more damage %, more range adding Psychic effects to his attacks (think Lucas and Lucario's tilts and Smashes) and more grab range (like I described earlier, making it disjointed) think of the move as a mix between Calm Mind and Bulk Up from the games.
However, it's obvious that while using this move, Mewtwo will be a sitting duck. That's why the move would also heal after being fully charged (slowly though, think 1% / 2% / 3% damage each time after holding it in for longer than 15 seconds, making it still risky in usage). Mewtwo would also be a bit heavier after using the Meditate move, while becoming more floaty in the same time, thus becomming a more competent character. The effects would likely stay in place for about 1 Stock long but; the longer you charge, the longer / stronger the effect.
To balance it out, the buffs could be 'knocked off' if Mewtwo receives too much damage (think 70% or up after the usage of Meditate). Or is just hit by an extremely powerful attack that'd make him lose his focus (say, Falcon Punch, or DK's charged punch). Though, the more you'd charge it up, the less likely the chance. After charging up Meditation, you'd see Mewtwo glow (similairy to DK with his B) and he'd be able to heal himself slightly. Powershielding also would become much easier when fully charged.
This way Mewtwo would still remain his Melee attributes of being a character hugely technical, campy and defensive. While on the meanwhile obviously buffing his offenses. Also, it makes prediction extremely important when playing vs him, as there'd be a difference between each stage of Mewtwo's Meditation. Shadow Ball, plus Confusion with reflection / grab ability would help Mewtwo remaining campy, and give him options without having to use Meditation.
Think of it as a "reverse Lucario". Making Mewtwo and Lucario somewhat similar after all.
EDIT: As for a better explanation on Meditation here's what I was thinking of stat's wise. Ranking up to Meditation levels 1 to 6 (reference to the games).
Meditation level 1 (hold B for about 4 to 5 seconds); Mewtwo just becomes a little faster, some moves are easier to sweetspot (like F-tilt), but no noticable difference in damage %s, or knockback.
level 2 (6 to 8 seconds); Mewtwo becomes faster (though this'll be his max. speed, he's not getting faster after this, directly) and a little heavier (normally being Yoshi-, he now becomes the level of Yoshi himself) and his normal tilts and Smashes do about 4~6% more damage (max.). Sweetspotting is the same as level 1.
level 3 (8 to 11 seconds); Mewtwo will become more heavy (about Yoshi+), and also a little floatier (not like Luigi yet though) which would make some moves like Dtilt become easier to combo. AAA and grabs get far more range now, as well as Shadow Ball and Confusion becoming stronger.
level 4 (11 to 14 seconds); normal attacks do more damage (about 8~9 more, considering sweetspots) and power shielding becomes easier. More knockback on throws as well.
level 5 (14~19 seconds); Mewtwo reaches his heaviest level, which is noticable from the start (before being Yoshi+ he's now moving up to Samus+ / DK- range) and most of his move now have the Psychic / Darkness effect where they where not before. Mewtwo in this stage flinches or loses focus less easier than former levels. From this stage, jumps also get a little better (as in, jumping higher, yet more slowly), boosting his recovery, but yet, he'd be easier gimpable by Dairs (yet, with additional jumps and weight it shouldn't be a problem too much). All of Mewtwo's moves have high, almost Ganon-like knockback. Combos are mostly lost, but Shadow Ball charges easier and does 30~33% damage now.
level 6 (20~30 seconds, after 30 seconds, Recover mode is on); shield becomes insta-Power shield and upon reaching this stage Mewtwo already recovers 10~15% (not much considering the damage he could get in between charging his move). Moves mostly have Ganon / Ike like knockback now (bit less of coarse) and Mewtwo plays as a full heavy weight now, with more speed. Has about 1.5 or in some cases 2 x the range and power in some moves while maintaining speed.
If not 'maintaining' Meditation (as in, not charging up whenever possible) would make Mewtwo lose stages in his power, and so would hitting him with a strong attack out of the move. Also, when Mewtwo is KO'd, he'd obviously be brought back to level 0 in Meditation, which'd mean he'd actually have the most disadvantage out of any character to be KO'd.