Again. Not asking for a full custom Palutena because I don't want to go there. I only want to give her access to lightweight. She will still function as she was intended to be played. She will not be overly reliant on lightweight. Palutena players have spent enough time at a disadvantage with counter to find other ways to kill without using lightweight. Lightweight will be a tool she will actually use compared to her counter.
I don't think Palutena
needs Lightweight, but it does make her otherwise mediocre kit more viable in terms of the opportunities it opens. That's a pretty big deal and it'd definitely make her a more consistent character in terms of followups and making use of her otherwise weak advantage.
The thing is, it won't solve her biggest issues. Palutena's an inherently defensive character, with her moves designed to reflect this; you can't just toss things out in neutral and hope to do well, you need to wait for opportunities and poke with what safe options she has. Lightweight won't fix her mediocre tilts and smashes and it won't really change her gampelan: she will still be a defensive grappler who wants to get the grab, she will still suffer in neutral and she will still have to fish massively for kills. It will definitely make her
better, but it won't necessarily make her
good. She'd need her other customs for that to be a reality. Cherry-picking one custom, even with the best of intent (and I do agree with the spirit of your message), won't fix what currently makes her a weak character; it will just mask it.
On the subject of gatekeeper characters, who do Pit and Pacman have as "gatekeeper" characters? Just about every borderline high tier canidate has one. Villager/Ness have Rosa, MM/Falcon/Olimar/Greninja have Sheik, DK has ZSS, etc. I can't think of who even serves that purpose for those two characters.
I can't speak for Pac-Man, but I don't think Pit has a gatekeeper. He has a few matchups that he doesn't really want to get involved in (Sonic, Sheik and ZSS come to mind), but nothing that he can't win with a bit of grit and elbow grease. I don't think there's any single character that stunts his potential viability. He doesn't really commit to one gameplan, he's got pretty decent options for most matchups: versatile kit, decent frame data, great (if somewhat gimpable) recovery, a pretty good projectile, good mobility, pivot options and grab reward that helps his footsies game - he doesn't really play one consistent game, so there's nothing that can really counter him in the traditional sense.
I don't think Pit gets mediocre results because he has a gatekeeper keeping him out. I don't think that's the issue, and I think most Pit players will agree with me. The issue here (you've heard this before; feel free to skip the rest of this paragraph if you're tired of Wintropy's Pit rants) is that, because he doesn't commit to one gameplan or distinguish himself in any impressive way, he doesn't counter anybody either. I don't think there's a single character that thinks,
"Oh, whoah, Pit! I can't beat him!" His diverse options and ability to play footsies well means he can be a very good character in the hands of a player with good fundamentals; but because of that, there's really no reason why you should play Pit at top-level except for reasons of character loyalty or as a reliable pocket. If you want a character that can reflect your fundamentals and has the options to play footsies with most of the cast, if you want a safe, comfortable all-rounder that's good at most things but doesn't have traditionally great options - why not just play Sheik? She
does have great options and she
is the safest character in the game in terms of matchup spread. If you're a top player and you have great fundamentals, why go for the weaker option to reflect those fundamentals?
The thing keeping Pit out, in my opinion, isn't other characters: it's Pit himself. There's not really much incentive to main him if you just want a safe, reliable character, because there are other characters safer and more reliable than him, and everybody at the top knows it. Nairo only brings out (Dark) Pit as a pocket or for fun, I don't think he's ever brought him out for grand finals in a national because he knows other characters (ZSS or, hell, Doc!) counter other characters better than Pit does. Even the undisputed best Pit main on the planet, Earth, pockets Fox in case he needs the matchup advantage. Pit can in theory win even his worst matchups, but there comes a time when you're just forcing yourself to play the character because you want to play the character. That's great and it's fine for certain people, but for others, they want to win and they want a character that will help them win. Pit can provide that, but he doesn't provide it in a quantity sufficient to make him stand out within a sea of high-tier characters with equally good fundamentals and even better matchups. That's what I think holds Pit back, and it's why I think that he will remain a consistent character with respectable results, but - short of Earth moving to the US or another top Pit main coming out of the woodwork to make waves in nationals - he won't be anything more than just a good, honest character.
EDIT:
Nobie
just beat me to it. I spent twenty minutes on this treatise, damn it...!
has no reliable way of getting in. You can kill 
