Hey - good-looking falco overall. Just some pointers from watching the most recent fox videos: Don't dacus so much. I realize that it worked a fair bit for you, but most opponents at higher levels will not be taken by surprise as much as the fox, and will shield the upsmash, leaving you open to fairly easy punishment. Granted, throwing a dacus in after a shdl at high percents is a pretty good kill-option, you shouldn't be using it very much, if at all, at lower percents, especially because you want to keep your upsmash fresh (considering it's falco's most reliable kill move). Along the same lines - try and limit your use of the gatling. If you whiff the da, you get a lot of lag, so tho it's flashy, it's not that great of an option except out of cg. Speaking of cg - I haven't had that much experience in the fox matchup, but I do believe you can get a couple more cgs in after 2, and end it with a dair. I do know for a fact that on mk, you can get 4 grabs and a dair guaranteed. Although, since you opt to go for 2-3 grabs and then gatling, the damage output may be similar, but that's just something to try out.
You utilized the iap a couple times, but throw a few more of those out there once in a while. It's good for chip damage and is quite annoying when compared with laser spam - just don't overdo it because your opponent might start to predict it and utilize a high priority move to hit you out of the phantasm. Also, mix up your recoveries with the phantasm - you lost a stock because you kept phantasm'ing right onto the stage where the fox was waiting, so try mixing that up with shortened ones or simply ones right into the ledge itself.
Try not to aerial straight into a standing opponent on the ground. You had some success with this, especially dair, but honestly that fox should have shield grabbed you each time you did that. When you aerial a grounded opponent, di towards them during the initial sh rising animation, but di away afterwards to avoid punishment. For moves like dair or nair, this will keep you from getting shield grabbed, and still damage or chip away at your opponents shield.
As always, avoid rolling and spot dodging needlessly - sd'ing several times in a row will not benefit you, and may even trap you within lag when you actually need to use the spot dodge. Against the fox, you didn't roll that much, but sometimes you still got punished.
Finish out your jab combo more often. It does decent chip damage, and if you don't finish out the combo, things like jab > grab won't work, because your opponent isn't conditioned to expect the AAA. Once you condition them to expect the AAA after the jab, they get hit by a jab and instinctively shield. This is what allows you to get the grab in. Simply going for jab > grab w/o making them afraid of the AAA first is generally not a successful tactic.
Specifically on the mk match - don't stick around when mk gets close to you. Walk away, run away, iap away, sh away, even sometimes roll away if you absolutely have to - but don't do what you did and sit there alternating spot dodge and downsmash/dtilt. mk's downsmash and dtilt outrange and completely outspeed yours, so there's no reason to sit there playing russian roulette, trying to get lucky and hit him before he hits you. Respace yourself by moving away or using ftilt/AAA, and then start over. Also, perhaps most importantly for this matchup, why are you trying to approach mk? He has no projectile, whereas you have a gun and your phantasm. Sit there and camp, retreat shdl and camp, camp and then phantasm away - do anything but approach him. Just don't get predictable with your phantasms because he will screw you over with the tornado. Like I mentioned before - way too much rolling in the mk match, and way too much dacus as well. Your mk opponent was not that great, but he still managed to punish you for some stuff.
You've got the tech skills down it looks like - just play smarter and work on some of the tactical aspects of falco.
Hope this helps :]