Norfair should probably stay banned. The stage layout allows for some camping near the degree of circle camping (just not as universal to the cast and not as much room to expand and exploit on this spacial retreating). The best strategy stagewise is to get the lead and find a way to run around safely. In the air, under platforms, under/through the stage completely, etc.
Summit will never be legal and there's no good reason to legalize it. Has a camping issue near approaching the degree of rampant circle camping. Being sent off to the fish is incredibly powerful/hard to deal with even if you escape his wrath.
Luigi's Mansion every single problem with the stage stems from the house. The stage would be perfectly fine without the house in the way. The house being present strengthens keep away games, and destroying the house isn't perfect since it will spawn again shortly (also comes at the cost of specifically taking time out of the match to destroy the house instead of fighting the other person, and at a certain point you're basically admitting to having to set aside any sense of gameplay in fairly frequent intervals to address an issue the stage brings up itself, that will not fix it in any lasting manner).
Green Greens is a bit iffy. Absolute requirement for this stage to even be up for consideration to be legal is ledge play regulated (even "weak" planking offenders get stronger here due to the multi edge layouts). The stage is absolutely atrocious in that manner even with MK banned. Now, under the context of a LGL for most/all/etc, it might be playable. Certain misinformation is spread about the stage, such as "Oh whenever the bomb glitch happens, you can simply airdodge through it" because there are different exploding glitches and hitbox lagging exploits. I've not done extensive testing on stopping it, but I came across 1 bomb glitch that seemed near impossible to stop (I think the only way to break it was to hit another bomb block that was in the same exact location as the one that originally glitched, BEFORE the glitch would set the new block off.) Airdodging, throwing projectiles or attacks or even people into it did not stop it, apples did not, etc. On another note, MK had some cool exploits on this stage but assuming he's banned that's nothing to worry about. 1 of them involved Uthrow putting you both under the stage and stage spiking/putting them in a bad spot. Others with shuttle loop and options off the edge.
Distant Planet only has 1 actual potential issue. The position near the end of the slope, that goes down under the leaf platform, is fairly powerful for many characters to stay in. It's a hard area to approach into safely and gives the person usually plenty of time to react in time to the other person's movements. For some characters, if you cannot keep up, it can turn into a semi circle of that position, top of the ledge, and the right side of the leaf platform. The walkoff IS NOT an issue or at least not a ban worthy one. Camping the end of this walkoff near the blastzone is also harder to pull off than normal walkoffs because besides Olimar (maybe tethers? Don't remember oh well who cares) your grabs will extend horizontal instead of traveling down the slope, making it harder to actually land the grab. It can be a better position to be in if you're dealing with a horizontal projectile user: Falco would have a much harder time lasering you endlessly if you are up there than if you were at the end of Bridge of Eldin for example. The pellets and rain are not much of an issue either. Again, the biggest issue is that position under the leaf platform at the lowest point of the slope walkoff, and characters that can maneuver safely from that position to other parts of the map while regaining that stronghold when needed.
Pirate Ship... idk. A lot of problems are temporary. Will probably bank on how much people like Water.
Skyworld has a semi/full circle for some characters and MU's camping problem. The stage, if the platforms were solid and unbreakable, would still be bad due to the platforms not being jump through in that kind of layout.
Pictochat would be acceptable if:
1. Clear warnings were given for a transformation coming (doesn't even have to specify the transformation about to take place for it to be ok)
2. More delayed start up or time period before everything drawn became active or walls became solid. Certain things are instant or near instant. That's a no-no, even if it's just a normally harmless wall that normally you could avoid or plan around given time/warning.
Pictochat being random and having effects that can be instant or near instant is bad. Some of the hazards are debatable, but again they would be much less troublesome with fair warning and the stage would probably be legal if this was the case.
Port Town overall is just a mess. It has a lot of unappealing stage facets that don't lead to good things. Cars that kill at pretty low % even on heavier characters is not a positive. The cars are usually given pretty fair warning, but that doesn't mean they are not a ridiculous hazard in themselves. Most "stops" on the track are very spacious, and the main moving platform missing edges is a con. There's no 1 universal quality of the stage that makes it seem banworthy (no edges in a lot of places might be close or most areas being very spacious, but everything is also shifting/semi temporary), however there's no redeeming quality of the stage either. Shifting from the main platform to an area that's large, but has cars coming, doesn't scream out "Great Stage" to 95% of people lol. Even when the platform stops in areas that are calm, you still tend to have large areas that don't promote fighting or being close to the other person, in fact many times if you are getting close to someone it's to avoid dying to the cars not to specifically duke it out hand to hand with the other guy. I would not have Port Town legal because I can't think of a positive or quality that can even come close to redeeming the cons.
Japes is interesting. Like Green Greens, the only shot this has is assuming ledge play is limited on a scale larger than MK+friends. With that in play, you have at best a coin flip for the stage to be legal depending on how much you dislike or how weak you think camping strategies are on this stage. The stage is fair sized horizontally, and massive vertically. Can give certain characters a massive amount of room vertically to run around (Wario being the main offender, MK second). Can give many characters advantages for camping certain zones depending on the situation. Characters not that great at approaching, can struggle to approach someone if they are forced to go airborne to meet them. The stage is broken up into 3 areas, and you have to jump float or basically move off the ground to get from 1 to the other. You can exploit this depending on MU and character and make it miserable for them to get near you. The Klap Trap is not an issue for the stage. Again, the main issue is that camping overall gets stronger, and that you can find silly MU's that turn this way specifically because the stage strengthens and/or gives different ways to camp (Many people don't know that Wario for example can literally ride his bike underwater, with options of getting out of the water soon, getting out normal, or getting out late, also depending on DJ and Upb usage you can change timings and locations. His case is pretty unique, but you have cases where camping under the stage can work, where camping and moving vastly upwards can work, where camping around edges ((without specifically grabbing them a ton)) can work, etc.)