I'm a Mario main. I HATE Mario dittos because they're extremely campy and boring. So naturally I feel obliged to show Mario mains no mercy with my Ganon.
Anyhow to actually comment on the matches, I really think you should recover high more Ace55, especially in those matches against Falco and Marth. The only time you should consider deliberately recovering low against Marth is if you KNOW you can edgetech his D-tilt. Most of the time Marth isn't really able to punish Ganon extremely hard if you're good about mixing up high recoveries and DIing carefully. All you want to do is condition him into letting Ganon get back on stage safely, and then continue with business as usual.
Also, I know it's a hard habit to break, but F-air -> Jab isn't always the best option. Throw in a few tilts, especially if you're out of range for that Jab. I also felt that your reactions out of D-throw were fairly weak at times.
Against Falco, you should learn to recognize spacings where it's safe to wavedash out of shield to gain breathing room.