WW84 had an appropriate level of cheese, I think. I wouldn't change the tone, and the moral is always a good one, especially when dealing with mythical characters like Wonder Woman's amazons.
Without any spoilers, here's what I would change about the movie. After you watch it, let me know if you think these would be improvements.
1) At the start of the movie, we're shown a young Diana learning(?) an important(?) lesson. Instead, I would start with Max Lord's childhood. We're shown it later in the movie anyway. I'd put it up front so we're compassionate with the character. This would also serve as a less transparent reason to bond with Barbara, as they could be kindred spirits, and only later we learn his obsession.
2) I would postpone the difficult thing Diana has to do. She still has cards to play at that point. I think she'd don her special armour hoping it'd be enough to protect her. When it gets shredded from her and she's beaten to the point that it's clear she can't win, only then she does the difficult thing, knowing the implications and that there'd be no warning. It would devastate her while she's already at her lowest point. Let her rage of what happens fuel her return to the fight and victory over her adversary.
3) Ignore everybody else at the end. In my version we start with Max Lord, sympathize with him, understand why he does what he does. So we need to end with just Max. Chuck the "I wasn't talking to you" speech. Let Max see the truth of what he's done to what he holds most dear. They kind of show that already, but muddy it. I'm just suggesting removing all the noise. Make it purely his realization. Make him alone do the thing that saves the day.
The rest of the movie, can stay as is.
