Wasssssuuuup maaan!!! I like it that you got sound, but I'll miss those songs.
Anyways, the Mario wasn't bad for just pickin him up, I do have a few tips for ya though. Most important thing I see is too much full jumping. You need to make your moves quick because Jim will catch on to the lag of the FJ and Dash back then forward to punish it. On the same note, keep the Uairs SHFFLed as well. Uthrow is your best friend vs a spacie, unless you wanna For Bthrow when on the edge. Dthrow is alright when at higher damages. When you caped his illusion and he just fell withotu teching(it's ok Jim, Twitch does it too), you're better option than Usmash is probably Dsmash. You wanna get Fox off of the edge so you can cape the Firefox or tilt/smash/fireball/cape the illusion. Your predictions of his movments were good, but sometimes you just weren't fast enough to punish him. This ability can come from incorporating DDing with WDing into movement mindgames, or just knowing which SHFFL to use at what range. Dash attacks are usually a bad idea, especially against an opponent that can CC very well. Speaking of which, you need to include a little more CC yourself. I'm not saying you didn't do it, it's just to counter all of Fox's Nairs and jabs, CCing can really mess him up and even get some grab combos started. One more thing bout SHFFLs, you use the Fair a little more than most Marios. You can use as much as you want and do pretty well, but most Marios find that the windup lag is just too much. Maybe you can try substituting some Dair approaches instead? You moved better in the match on FD, but you were still a little predictable. Try approaching a little higher or lower than usual, or you could even fake an attack and draw him out, then punish.
I hope this wasn't too long or anything, I just wanna help your Mario man. Good to see some Kidz vids again.