Well, with the time I have now, let's start tackling Danny.

[@Crimson Flame]:
[list][*]First: The thermos. There's no Ghost Zone to dump people into, so it's really just active until it hits capacity (and even then there are issues to be concerned about). Then there's the whole issue of the actual effects it'd have on undead or earthbound spirits and that's a whooole other can of worms.
[*]You don't really need to break down every facet of Danny's ghost form for the sake of explanations, if I'm being honest. But there are a ton of smaller issues here within his powerset that I should bring up.
[list][*]Possession of others. No. Let's not. I'm well aware that he uses that ability more often than not to get back at his bullies (among others), but it is inherently an ability that takes control away from other players, which is an issue regardless of use case.
[*]Dream access: there's a whole bunch of stuff I could talk about here, but at the end of the day it's an extension of the possession issue. Like mind reading, but also pretty invasive even if there is no directly malicious intent.
[*]Ability to use a weapon does not equate to skill with a weapon, to the point where I'd say if he managed to swing a sword around two or three times it wouldn't count as being skilled in swordsmanship. To expound upon this further: Danny Phantom (as a character) has limitations imposed on him by the medium in which his series originates (that being a cartoon series). There is no reason to animate complex swordplay if simple swings do the trick (a la comic book impact frames). He just can't reasonably [i]have[/i] skill with any sorts on random weapons unless he has shown reasonable skill with the weapon and not just "able to use it because plot gave him one".
[*]Casual intangibility. Like, okay, yes, he's part ghost in ghost form which should enable some level of phasing attacks, but this also puts the onus on the GM side of things to create encounters that he can't just cheese because "lol dive into the earth and yoink enemies into the ground and hope they can't respond". In context of the show, it works fine because a vast majority of his enemies are also ghosts and thus play by the same rules, but that doesn't apply here.[/list][/list]
There might be more here that I haven't caught at a glance, but for a first pass, those are the issues that I noted. Might say more later, but that's it for the moment.