I don't have time to watch all the videos, but if you want me to analyze ONE more specifically please ask me to do so.
For now I'll talk about the first match against Bowser on Frigate.
Alright so, I understand it's a small stage and everything, but you didn't demonstrate good laser use. I saw you SHDL maybe ONCE the entire match. Otherwise, you would full hop, wait until you almost hit the ground, and then fire. Not only is this a waste of time, but it's more difficult to get consistent silent lasers with a full hop, let alone a short hop, so you suffer lag because of it. And most of the time, you landed right next to Bowser, just showing how bad an option it is to give him time to get under you, and then punish your solitary laser. I suggest learning SHTL, or use SHDL more at least, never standing still after you land. Either dash away after landing, or approach with running shield.
You missed a very crucial step in combo-ing Bowser, and that is Short Hop auto-canceled Fair. Every time you used it in a short hop it didn't cancel, giving you lag and rendering you unable to follow Bowser when he is one of the most susceptible to Fox's combos. I saw you auto-cancel upair, so you should definitely have the ability to auto-cancel Fair, it's really easy. I did see you using rising Fair to recover once or twice, so at least that's all good.
Fox's vertical spacing is among the best in the game, but you weren't using it quite correctly. I saw you using SHAD at the beginning of the match, which is good, until it became overly predictable. You have to be able to land BEHIND the opponent's shield with SHAD, making it harder for them to punish you due to positioning, and making them deal with your frame 3 uptilt. I also saw you full hoping, and landing with AD... that is not a very good idea... This is where your shine stalling comes into play so that you can create openings for yourself. Just hoping that your opponent doesn't use a move that will outlast your airdodge is not a good strategy, but waiting for him to whiff a move is. I saw you shine stalling off the stage, which is fine if your opponent was trying to set you up. But Bowser isn't exactly the fastest character, so I suggest against using shine stall until you are forced to use Firefox. I saw you using Firefox too much as a recovery move, and you're lucky Bowser isn't especially good at gimping. Get on stage as fast as you can is always the goal with Fox, but the point is to make sure it's safe, not to waste as much time as possible.
Also, Nair OoS more, it has just the right amount of knockback you want without stale-ing your trump card upsmash. Also, use more jabs/learn how to jab cancel. Fox's jab is frame 2, and I saw some attempts at landing it, but you either didn't hit with it or use jab to it's fullest potential.
Overall your Fox seems very pensive. It's good to think, but Fox is a character that has simple routines you can perform while you think that both buys you time and accumulates damage/pressure. An expert Fox player never rests. The only time you should be doing nothing is if your opponent is too far off stage to do anything productive, and you're waiting for a possible opportunity to gimp.
However, there are those who do like to be patient with Fox, letting aggressive opponent's attack them first and following up with a lot of punishes. This isn't always the safest route though, as your opponent may just be approaching too safely.
If you didn't get anything I was saying just ask. And keep up the good work :D.