I'll watch over all the ICs stuff more closely later, but some initial remarks:
I don't have much to say on the 69% set since you just played better than he did and since he doesn't know the match-up well. Good stuff.
Regarding Marth, your blizzard wall could be much better. You pretty much always just have Nana do a standing blizzard; there are lots of little variants of this that work considerably better depending on the curcumstances. For example, one little trick is to have Popo run forward and shield after Nana blizzards; the weird force that Popo exerts on Nana causes her to drift forward and make the blizzard reach farther than it otherwise would; this is also nice since the opponent might think you made yourself more vulnerable by running through the blizzard and thus try to move in to capitalize, only to get hit by Nana's magical sliding blizzard. Something that's really, really good I didn't see you (in the first couple rounds, which are all I've watched of that set so far) is a short hop Nanapult forward; there were a lot of times when Marth was a bit outside of your reach when you kept just doing ice block -> standing blizzard -> ice block -> standing blizzard over and over again when you could have just hit him with short hop forward Nanapult blizzard. Your punishments off blizzard when you do connect could also be better; you often try to grab, even when Marth is too high for that too work. I personally like to dash attack after blizzard since it combos well and is fairly reliable; utilt is also probably good, but hard to space well since you can't do it out of a dash; usmash is probably really good here, too, if a little slow. If Marth is on the ground and CC'ing the blizzard, you could try to fair over it if you think he's going to CC dtilt through the blizzard. There were also times when you had a grab on Marth at a high percentage and just did something like dthrow -> fsmash, where dthrow -> charged usmash would have KO'd easily.
Regarding the Ganon match-up, there are lots of little things you do fine, but a few little mistakes or things you could improve upon that cost you a lot. Starting the round with drop down > blizzard didn't make a lot of sense; blizzard stops horizontal approaches, yet he was above you, and he punished you pretty badly for it. Although a little odd and seemingly contrary to the general rules of stage control in this match-up, I think a good idea against Ganon in this starting position is to wavedash backwards towards the edge and then waveland towards the center on the bottom platform; this will ultimately put you in an okay position and let you get there without having to worry about Ganon's starting shenanigans too much; if you start doing this and it looks like he's going to try to force you by the edge, you can instead blizzard before landing instead of wavelanding towards the center. This is mostly theorycraft, so I wouldn't be shocked if some of this doesn't work as well as I think it would; I don't experience this situation much since I never use the third port.
Your edgeguarding could be a little better. You shouldn't be afraid of jumping out and throwing out a nair or bair to hit Ganon if you think he's going to wizard foot after double jumping. At really high percentages, you could just grab the edge, force him to recover on stage, and then KO him with a bair or dsmash or something like that. The awkward thing that could happen here is that he might hit Nana with up-B, but if that happens, you should still be able to bair him afterwards on reaction.
Another little thing that cost you a lot in a couple instances was not making good use of your shield. You don't need to constantly have it super-huge the way Chu does, but making sure it covers your whole body well and angling it appropriately can prevent shield pokes, which can make a big difference against Ganon. You also shouldn't voluntarily go on platforms against Ganon unless you're very confident that you won't get punished badly for it, which doesn't really fit into this part, but is on my mind since you did this once right before one of the aforementioned shield pokes.
Be very cautious about when and how you blizzard camp Ganon. You only tried it once, but the way you did it caused you to get punished. The big deal in this particular instance is that after the blizzard missed and evidently wouldn't hit, you followed it up with short hop ice block. Ganon was approaching from above, so this wouldn't accomplish anything. Something you could have done to stop the bair he hit you with would have been run forward short hop uair, although that is kind of risky and would lose to some other things he could do. Another option you have is to, once you realize that the blizzard won't accomplish much, wavedash backwards. At the very least, this will make Popo safe, and it will likely pull Nana back a bit, which could save her, too. This is what I would probably do in that situation. It also probably wouldn't have hurt to space yourself a little back in the first place.
An obvious remark is that your grab game could have been a lot better. You can dthrow CG Ganon on reaction pretty easily at low percentages, but you occasionally messed that up. I know Bizzarro Flame is very good at getting out of reverse dthrow > dair in really bizarre ways, most of which involve some sort of hard SDI down and backwards so that he immediately lands on the ground so that he can grab/jab/fsmash/*insert other weird option here*/etc.; if you anticipate that DI, dthrow -> usmash is probably really good, and at higher percentages, stuff like dthrow -> run forward bair is also probably really good.