Mewtwo used Telekenesis on teh gyarados trainer. He's not small, nor stationary, and it was instant. SAo logic would dictate he's capable of doing it to goku too. Even Sabrina has used Telekenesis on people before, if you recall when she threw Ash and friends out of her gym. And she is nothing comapred to mewtwo. I don't know where you got the idea it only works on small stationary things, but it doesn't. :\ And there are other animes where disable is instant, albeit it's performed differently. For example, in yu yu hakusho that one psychic all he had to do is step on someone's shadow and they're disabled. and that other one, he had a power where if they say "hot" they lose their soul, therefore being disabled. And that was instant. Ik had told you they've had psychic abilities work instantly in other anime's before, and the proof was in teh putting. But you didn't listen to me, which reall isn't a surprise.
and SM told you why Mewtwo would win the fight. Because he can use telekenesis to throw Goku around like a rag doll and if Goku somehow manages to break out of that, he can still use Telepathy to torment goku mentally. mewtwo's mind is superior to goku's so Goku really won't be able to fight it. And mewtwo doesn't have to concentrate, He never had to concentrate to do anything he's ever done. His mind is so powerful, everything he's done he's done at his leizure, meaning he wasn't exerting himself in anyway to perform those moves. Again, proof is in his body language.
and psychic is a telekenetic attack, meaning it doesn't have to take a phsycial form. Only Psybeam and Psywave do, as they have a phsysical definition , the wave and teh beam. If you recall, whenever a pokemon uses Psychic, all that happens is teh POkemon's eyes start to glow and the opponent becomes ensnared in teh attack. There is no physical thing about that.