2 things I'd note were I saw you going for Dair a lot whilst you were above Ness, generally Dair is too slow and low priority to beat out any Up Airs, particularly Ness' who has insane prio on all his Aerials, so AD/Mega Bomb/FF Uair are generally safer.
Also you can use the Mega Bomb as a frame trap of sorts if you get him off stage and lay it at the ledge, you can wait at the spot where he has to roll up and cover virtually all get up options, if he tries to wait out the bomb with his invincibility, Low Charge Shot!
Very solid overall though
A bo3 I had vs a good Mario, I go from good to garbage to good real quick