First I'm going to give R.O.B. a bit of a personality in a "parody" project. He should be kind of haywire and short circuiting... that's the theme I'll work with.
The way I see it, the most important features for a character in such a parody would be the Special Attacks. So I'm going to start with those attacks:
Neutral-Special (Laser)
This should have no charge to it, as the diode in his head will be overloaded... maybe it should flash consistently as though it is always fully charged.
--The Laser should always be fully-charged, but each time R.O.B. uses it, he should get recoil (knocked back) and Trip.
--There should be a one in 10 chance that it turns into the Diffusion Beam (his Final Smash) without the invincibility he normally gets from the Final Smash and sans recoil/knockback; This should last for a shorter duration (maybe 10 seconds instead of 30 seconds).
--There should be a one in 100 chance that his Diffusion Beam has NO HITBOX, and in addition to the conical beam that is projected, he should have a picture of Professor Hector projected in front of him (possibly with text that reads "ERROR ERROR")
Up-Special (Robo Burner)
Not much should change with this, as it should function normally as it's a major part of his Recovery, but if it's possible it would be great to give it added smog and maybe every once in a while a backfire like an old car in need of a tune-up.
But two major additions:
1) There should be a 1 in 8 chance of misfire. The "misfire" should essentially be like Luigi's misfire on his Forward Special, except R.O.B.'s would go verticle instead of horizontal.
2) When R.O.B. exhausts all his fuel he should explode. This could just be a special effect that just freezes him in place momentarily and turns him black with ash, or it could have a hitbox.
Forward-Special (Arm Rotor)
This attack is in major need of change seeing how it is sooooo bad. But we're not going to break this in a too-good way, we're going to break this in a funny way.
--This attack should appear like normal when used. However, when an opponent gets caught up in it, the attack will have an effect very similar to that of Toon Link's Up-Special or similar to Meta Knight's Mach Tornado.
--The major drawback of this attack is that IT DEALS NO DAMAGE.
--However, after an opponent is spit out of it, R.O.B. will spin and fall over (Trip) and the opponent will have their controls reversed (up is down, down is up, left is right, right is left).
If this proves too difficult to make work, something similarly silly can happen to the opponent after being spun in circles.
Down-Special (Gyro)
The Gyro is so much fun as it is.
Keeping with the theme of short-circuit R.O.B. I would suggest
--The Gyro always be given a wobble animation so it looks off-kilter (don't change it's other properties, just the appearance).
--The Gyro may have a "misfire" on it as well, in which case it will be automatically full-charged and then shoot out of the Stand vertically.
Here's a few suggestions that may make it more broken-fun:
1) Give him two
2) Make the spinning Gyro on the ground cause Tripping instead of damage.
3) Make random items shoot out of his Charger (e.g. Bananas, Turnips, Mr. Saturn, Bob-ombs, Mr. Game & Watch...)