Fridge Brilliance: Chairface Chippendale's plot to put his name on the moon didn't seem to pose any atmospherical or environmental danger, and technically wasn't illegal since no one owns the moon, so hilariously, everyone spends the entire episode flipping out for no reason at all.
Technically speaking they could nab him for vandalism of the commons/ecological vandalism, illegal graffiti, conspiracy to commit theft, handling and usage of knowingly stolen goods, or unlicensed possession of Weapons of Mass Destruction. My money's on the latter.
Reckless Endangerment of Human Lives? That's a thing, right? Carving letters (let me see here, the letters were about a third the height of the visible surface, in the middle, and the moon's about 2000 miles in diameter, so about 6300 circumference, half of that, a third of that woud be) 1050 miles high could, I don't know, dislodge debris that falls to Earth, or de-stabilize the moon's orbit, any of which could be devastating here on Earth, both to civilization and possibly to life in general. Plus, the guy's a jerk.
Fridge Brilliance: In ''The Tick Vs Filth", the Sewer Czar makes intelligent minions because stupid minions didn't work out too well for him in the past. However, the Filth minions start realizing that their creator is actually kinda crazy and not acting in their best interests, later ending up switching sides. While the obvious moral of the story involves Judging A Book By Its Cover in the case of The Urchin, one could say there's another moral about independent thought and not following leaders who use scare tactics to get them to work for you.
Another version of the aesop is to not let others' perceptions limit you. Sea Urchin, normally a Rain Man parody mixed with Aquaman, is described in his home environment as the Apotheosis of Cool, and given that this is the only sewer-based episode of the series, implies copious amounts of Offscreen Moments of Awesome as Sewer Urchin handles his own domain so capably that nobody even notices when something down there tries. Similarly, the Filth are initially loyal to their creator, but when they realize he sees them as a Slave Race, they openly and respectfully question him well before leaving. Sewer Urchin and the Filth both care very much about their allies, but choose their own paths regardless.
Fridge Brilliance: The Tick's animal-theme and powers actually do add up. Real-life hard ticks have incredibly durable carapaces, so much so that they are hardly any worse for wear if you step on them or otherwise try to squish them (Do note that they're only this durable when not engorged with blood). If, like Spider-Man, this durability would be increased to human-sized proportions, you'd indeed get something close to nigh-invulnerability. Not to mention the proportional strength, as ticks can cling very tightly to hosts. Finally, male ticks hardly drink blood, as they do not need to metamorphose like the larvae and nymphs and don't need to produce eggs like females. Males drink just enough to sustain themselves. The Tick himself is an adult male, so he wouldn't need to drink blood. He can get enough sustenance from regular human food.
True, though the 'antennae' do resemble tick limbs. The front-most limbs of a tick have antenna-like functions too: they contain sense organs that help the tick detect fluctuations in temperature and carbon-dioxide concentration. This helps them notice or find hosts through their breathing and body-heat. Since The Tick spazzes out completely without his 'antennae' they could actually be those same sense organs... albeit placed very oddly.
It's heavily implied that Tick's "antennae" function like his inner ear in regulating his balance.