Penumbra having a hard time adjusting to life in Earth is actually in line with her character as she refused to even make an effort to get to know Della while Della was on the Moon.
Why wasn't the news focused on Webby and Dewey nearly DYING? Easy, they are used to Glomgold's efforts to destroy the McDuck family and must have assumed that this was all part of his plan.
Penumbra finds Earth's gravity particularly troublesome since, being much stronger than the Moon's, she doesn't just feel herself heavier and slower than usual, but pretty much everything moves and falls faster than she's used to, which is a big problem for a warrior. The other Moonlanders have adapted well enough, but they're not warriors like Penumbra, so regular earthling physical activity isn't that exhausting, 'specially since, as Penumbra and Lunaris had shown, their species is physically tougher than the average earthling.
Yes it is expected Glomgold wouldn’t care if his rides don’t meet safety standards because he’s evil, but his behavior ultimately foreshadowed his Ferris wheel was actually a poorly designed cannon to destroy McDuck Manor in public. Considering his ride fell apart and his weapon failed, it’s clear Glomgold’s lack of regard for safety standards makes him His Own Worst Enemy.
Adding to this, it makes sense why Scrooge hasn't been bothered by Glomgold's reputation as Earth's savior. He knows Glomgold will ruin his good publicity eventually with one of his hair-brained schemes to destroy him and then all that goodwill will go down the toilet.
Penumbra flinches when she sees the Penny Arcade.
Louie is watching a rerun of Ottoman Empire because he likes knowing how it ends. The rerun is from the Randy Johnny breakup so of course he knows how it ends. Louie got them back together when he hired them to make a ottoman for him.
Della letting Dewey and Webby go ride a dangerous amusement park attraction seems like a bit of character regression but there are reasons.
The last time she tried being a stern and responsible parent backfired with Louie. Her efforts with him left him at the mercy of Scrooge's worst enemies, set up the circumstances for Louie to claim Scrooge's fortune for himself and wound up with an invincible super strong zombie chasing him, which then ensured he learned his lesson. By contrast being more open minded and a bit indulgent hasn't led to much trouble so she's likely sticking with a more gentle hand approach.
A dangerous thrill ride is honestly on the very low end of troubles the Duck family has dealt with so she likely doesn't see much issue with Dewey going on one.
She sends Penumbra with them and because of their friendship knows the Moonlander will step in if anything too horrible happens.
It's been implied that she and Donald were raised in a fairly free range fashion by Scrooge so she doesn't see much of a problem with Dewey hauling off for something like that.
There is a simpler explanation; Della just didn’t know Glomgold commissioned the ride at the time Dewey asked (she didn’t see the commercial because she was in the hangar) and it isn’t until the end Della says she shouldn’t have let Dewey go on the ride. Dewey did refer to the ride as a “death wheel” without any context, so that would easily be taken as hyperbole, which is a normal thing to do when describing thrill rides. As far as Della knew, the chances of Dewey and Webby getting hurt or killed riding a Ferris Wheel is significantly lower than adrenaline-inducing rides like roller coasters. Now, if Della knew the ride’s official name or that Glomgold was behind the ride, Della would NOT trust the ride’s safety at all, and it would be a VERY different conversation.
Glomgold is a surprisingly Benevolent Boss to Gibbous. Consider how Glomgold is egocentric to an extreme and loves his evil schemes. Gibbous drinks up all of Glomgold's self-promoted hype and eagerly goes along with any crazy thought Glomgold comes up with. Of course Glomgold will be nice to Gibbous, he's basically the perfect employee in Glomgold's eyes.
Not being mad at Gibbous may come down to the fact that Gibbous legitimately didn't know he wasn't meant to call the safety inspector. Much as Glomgold deflects blame and criticism he also acknowledged that he used a gesture that Gibbous said he didn't understand, so Glomgold couldn't backtrack.
Penumbra utterly fails at every fun Earth activity Webby and Dewey show her, including rollerskating. She suddenly excels when saving them from Glomgold's Ferris wheel. The sudden competence makes sense befitting her warrior nature as she's engaging in an action to save lives giving her a reason to do something well as opposed to doing something for enjoyment.
Logically, fixing her ship would’ve been a lot faster if Penumbra had just asked Gyro to help, since he did design the original Spear and the Moonlanders’ ships were based off of that. But, knowing Gyro, and seeing how clumsily Penny is doing, Gyro would easily identify all the wrong things she did. Since Penny wouldn’t have the patience to hear Gyro’s criticisms and follow his precise instructions, she’d literally throw him out.
The whole episode serves to highlight Penny being a Distaff Counterpart to Donald himself. Between all the abuse she suffered, her having to learn to "relax" on Earth after spending much of her life as a soldier, and her being a foil to Webby in seriousness. Turns out in this universe, Donald isn't the one who gets stuck with all the bad luck.
When Launchpad asks Dewey for advice on how he should interact with Penumbra in the wake of their awful date, Dewey is clearly a little awkward and out of his depth. As shown in "A Nightmare on Killmotor Hill!", Dewey's at the maturity level where the concept of a romantic relationship is confusing/frightening, so it makes sense that he's uncomfortable with Launchpad bringing up the topic.
Penumbra says it’s rather evident the Earthers need someone to protect them, but Gizmoduck has already established himself as Earth's main protector. If that were true, then Gizmoduck would’ve shown up to save Dewey and Webby. Of course, it's not due to lack of trying; it's already known he can’t be everywhere at once and gets swamped, so Penny’s statement holds and he would definitely need all the help he can get. Plus, Penny is a seasoned warrior from an advanced civilization, and she could easily eviscerate him even with his tech and armor, which means Gizmoduck wouldn’t stand a chance against threats that could match her.
Fridge Horror
If Penumbra hadn't saved Webby and Dewey when she did, Launchpad would see his best friend and Webby die which would have most likely resulted in him driving himself crazy with guilt, Della would have had to live with the fact that she allowed them to get on the death trap Ferris wheel, Donald would have became even more overprotective over his family, Beakley likely would have never recovered, Lena and Violet would grieve over their best friend's death and Scrooge would have led a murderous grief-filled vengeance against Glomgold for being responsible for the deaths of his great-nephew and adopted niece. Which would have caused the entire Duck family and their allies to go after Glomgold, thus allowing F.O.W.L to steal the world from Scrooge while watching the show.
Lunaris is STILL in orbit. Though he hasn't been seen in person...
The Moonlanders are having loads of fun on Earth, but they'll eventually learn that not everything on Earth is fun. At best they'll learn about some of Earth's nastier things, such as crime and poverty. At worst, they could be the victims of these things or accidentally harm somebody and get into potential trouble.
Not to mention to bigotry they'd face after the Moonvasion. Sure the episode downplays it in this episode but it's still there.
Penny has just seen anthropomorphic ducks feed regular ducks, and is already confused as it is. If anyone tells her ducks can be eaten, she'd think the Duck family are cannibals.
Not to mention her reaction to finding out burgers are made from beef and there are anthropomorphic cows.
Of course, people go to zoos and feed the monkeys, so, if one puts any stock in the theory of evolution, perhaps this one isn't so odd after all....
