Mii Swordfighter's moves could have easily went to a unique Chrom instead of Original Character Donut Steel Swordsman,
I see your point here, but creating generic swordplay moves came out of nowhere like they did with the Mii Swordfighter would do little justice to Chrom IMO, and I think that it was exactly what Sakurai didn't want to do. The special moves for Fire Emblem sword users are not something obvious to create, most of Marth's and Ike's special moves have obscure origin based more on concepts than actual moves; for example, according to the wiki, Shield Breaker could be inspired from the rapier's ability to inflict effective damage against armored units, and Dancing Blade looks like the Astra skill, a technique that only existed in Genealogy of the Holy War and Thracia 776 (during the Melee times) were Marth never appeared. The only obvious special move being Ike's Aether.
The Robin Guidance is proof that Sakurai is hypocritical when it comes to certain characters, no two ways about it.
I have to admit you're right on this one
If I had an unpopular opinion to say here... eh, I love the Mii Fighter feature (I guess it can be called unpopular, the Mii Fighters got less than 50 % satisfaction in the Rate Their Chances final days). At first I didn't care about them, but then I tried it and started to think that it was extremely fun. I'm also glad that they didn't get a moveset based on Wii Sports or something, not only it was what I feared prior to their confirmation, but what's the point of creating a Mii based on your favourite fictional character if it's to have a moveset based on Wii Sports? The Wuhu Island stage is here to represent Wii Sports.
Also I don't think that the Ice Climbers will return in the next Smash game, regardless of if the next handheld generation (assuming we get a new portable Smash in the future in the first place) will be able to make them work properly, UNLESS they get a KI:U-like revival. Smash was literally what made them still relevant due to them lacking a particular importance towards Nintendo's story like other retros (G&W, R.O.B, DHD). I think that their only chance to return is either an Ice Climber IP revival or Sakurai absolutely wanting to bring back their gimmick, both of those being unlikely IMO. And I don't see the point of having solo Popo with Nana as an Alph-like alt, their gimmick potential is the reason why they got their playable role in Melee in the first place.