Morrison is who I'd consult with for BOTH characters
You can consult any modern writer with a brain, just like you can consult half the people in this forum, everyone in their unified criticism seems to know the simple key to the character. JMS could probably write an essay on what superman is about and it would no doubt put to shame any of our "essays" on the property.
Like I said, Morrisons take on the new current youthful superman is pretty silly imo, but I respect that it's just that, a take. WB commissioned a take with MoS, something maybe not just for certain fans that have a check list of things that will make them happy or else. Such as a villain ending up in a prison the way all superman villains do(except for the times they don't). But I digress, If I had hard about the details for MOS and the green light for WF a year after Returns, I'd probably jump for joy. As good as something is there is always going to be someone else that wants something more.
Morrison used to be my go to writer but sometimes he get's weird. That final crisis series is just too weird for me. His Xmen run is awesome but weird, I much prefer Whedons. Who get's the characters more? Who had the better run? I'm sure both these guys could tell us what works about Xmen, however their runs are about different things. The producers of MOS(yes all of them) probably get superman but their film is about certain things. Explaining how Waid get's superman after Kingdom Come is not the same as explaining how he get's superman after Birthright.
Everything has it's place and I think when it comes to "getting" superman, all of these folks have something of value to add. Bruce Timm being a good example of hit and miss ideas that depending on the day of the week, fan boys will usher forward as the ultimate consultant.
There is so much Superman in MOS, it's just a shame more people can't seem to agree if there was enough.
There wasn't enough humor. There was humor which I all liked, but there needed to be more times of levity. Especially towards the third act. I think the last humorous moment was when Superman got his powers back and broke out of the operating table.
It doesn't hurt to laugh. Humor does not equate to cheese which people here love to confuse.
Superman is Superman. He is a lighter character. Somber and serious are two different things. That doesn't mean he can't be taken seriously, which he was, but jeez, by the end of the film I could have felt slightly more upbeat. It was hopeful in a sense, but that is part of the flaws of the overall screenplay.
It's all a matter of opinion.
For example you say the humor ended on the operating table, though I'm sure if you think hard enough you might find a few more moments of induced levity. What sucks is when people don't think hard enough in their memory and then apply statements about the matter. Such as, "the film needed humor in the second half cause that would equate to balance and films need that."
Whats more is when the levity is objectively there for the purposes you all suggest it should be, but then another group of detractors sound off about all the things wrong with "I think he's hot".
It's all just opinion, and no matter what you do, there is going to be criticism.