I think its worth pointing about tap jump that that level of precision (which isn't that hard) is also required for things like dtilt on a platform. Its more of a matter of preference what control configuration you have. For me, I always have tap jump on whenever I play any character (yoshi, cuz up b). This makes jump cancel grabs easier. Likewise, I leave both r and l to shield so wave dash OoS is easier (using a temporary claw for hover stuff).
Again, its all a matter of preference, but I wouldn't say that you want tap jump off for easy up tilts because 1. They aren't hard 2. It develops a pretty important skill used in many other areas of smash 3. A personal preference anyways. I would have worded it more along the lines of "if you are struggling with utilts/up airs, what I do is this, it might help".
As for the rest of the guide, I thought it was very informative and highlights how Mewtwos neutral and over all gameplan (I was expecting a comparison to Marth, but it was a good enough explanation as is). The only other suggestion would be more emphasis on how good Mewtwo's grab game is. Great Guide!
