Stormy's motivation is not in question here. She was trying to make money on the story. It's Trump's motivation that is salient.
That's on you since you implied it made a difference whether the timing was set by Trump or Daniels, and the answer was Daniels.
If Trump was trying to prevent the story from becoming public knowledge to his loved ones, the cat was already out of the bag, and no NDA was going to stop it.
Without open confirmation, or if Daniels denied it publically (which is also not illegal), it would help. Ergo, moot.
It's not just about misappropriation. In this case, it was using funds for a campaign that were not reported as such, not using campaign funds for non-campaign purposes. Or are you using "misappropriation" in a different way?
Personal funds are not inherently campaign funds, ergo they can not be "misappropriated" for a non-campaign use.
It would have been a misuse to use actual campaign funds for this.
Moreover, it's fundamentally not why we have campaign finance laws to prevent or force the disclosure of personal expenses paid for with personal money.
And if a case is a "loser," does that mean it is automatically legal and not breaking the law? 
Yes. If a case is unwinnable because it's a nonsense claim, it means the conduct is not breaking the law.
Just like if I tried to convict you of murder because you cut down an oak tree. The case would be nonsensical, even if the point of the murder laws is to stop unlawful killings, and it was unlawful to kill the oak tree.
If taken to the extreme, perhaps. Taken to the opposite extreme, paying for hours of TV commercials advocating for a candidate is not a campaign contribution if they also plugged a specific brand of toothpaste at the end. 
You are already close to the ridiculous extreme. Again, you seem not to understand that you want to treat conduct it would not be legal to pay for out of campaign funds - and that a candidate would therefore be required to pay for out of pocket - as a campaign expense solely to force it to be disclosed. There's no world in which that makes real sense.
Putting commercials on tv to advertise reruns of the apprentice was not a campaign contribution either.
Or if you want to get real, what about all the misleading and free support that flows through Hollywood. I mean, even if you discount the opinion spewers on the news channels, you still have things like Hollywood basing characters on specific politicians - I mean hello "Madame Secretary." Did they disclose that contribution?
Not every thing in the world is intended to be covered by any convenient legal theory. The laws you are talking about are specifically designed to prevent the misuse of contributions by others, not to limit what a candidate can spend on themselves. The interpretation of "mixed use" items has consistently been to be skeptical of treating them as campaign expenses specifically because the misappropriation of those funds is what the law was written to stop. Turning the entire history of the law, its purpose and its enforcement on its head to try and manufacture a legal problem when a candidate pays for a personal expense with personal funds is an abusive joke.
What makes you think paying off a woman to protect a campaign is the same as getting a haircut?
Just a difference of scale under your theory.
I am no lawyer, so if you would like to explain how the laws which so many pundits were referring is not applicable in this case, I'm interested to hear it.
You're clearly not listening.
Quit listening to pundits. They love to assert bizarre interpretations to create a headline.
Once again, her motivations are not salient to this. Did Trump pay her off to protect his personal reputation, or to protect his campaign for President?
Or for both reasons, or for neither reasons, or for a dozen. To win this case you'd have to prove it was the sole reason (actually prove it) and even then it's still most likely a loser.
Sounds like, by your standard, nothing is.
Does it? Maybe actually spend some time learning about campaign expenses and come back to me.
No, you're trying to make everything equivalent when they are not. Just because paying off a fender-bender doesn't need to be reported does not imply that paying for TV commercials doesn't need to be, either, or paying someone a NDA doesn't need to be reported.
Then describe the legal/logical theory that separates them. You know what people actually do when they are trying to make an argument.
You don't have history on your side, no one's been found to have violated these rules on this basis, if fact worse cases have lost at trial and been derided.
You don't have purpose on your side, it's not why the law was written.
You don't have logic on your side if something like settling a car accident to keep it off a police blotter isn't covered and you can't differentiate why it's been considered a violation to use campaign funds to buy clothes to go to an event.
From what I understand, the law says that contributions to a campaign must be reported, even non-monetary, "in-kind" contributions. Trump made a contribution to his own campaign in the form of a NDA payment to Stormy.
Except, there's no reasonable basis to think that was a campaign contribution. Show any case where such has been found to be so in the past, and differentiate the Edwards case, and then come back to me.
You don't get to make up a fact.
He tried to hide it by various devious means and by out-and-out denial that he ever made it. That appears to me to be someone trying to break the law and hide it.
That appears to me to be someone hiding legal conduct that it was legal to hide.
Am I understanding you correctly? That breaking the law is primarily determined by whether there is a "winnable case" or not? That, in fact, if the case is not "winnable," is it automatically legal? 
It's like we're debating global warming and you just keep repeating that the Earth isn't getting hotter cause your fridge is making ice.
What exactly do you think law is? There's no conduct here that's an actual campaign finance violation. It's only by an absurd, aggressive, never held up before and actually found to be a loser version an interpretation that you can make the claim. So yes, in this case, the fact that this is not a winnable case is evidence that this is not illegal conduct.
