Remove the letters S, O, U and L from the name "Elrod Purvis" and rearrange it a bit, and you get "Dr. Viper".
Make that double, as those missing letters fit perfectly with him being soulless.
The Pastmaster was called "Tidshärskaren" in Swedish, which roughly means "The time-ruler" or "The timelord."
Dr. Greenbox's sudden bout of madness and FaceHeel Turn and helping Zed isn't exactly out of nowhere, at least not to how this troper interpreted it even as a kid. The whole time, Greenbox's dialogue about Zed had this air of hidden awe at the lengths his creation was going. It just kept getting more obvious as they were climbing Zed's structure from within. Once the moment came to destroy the core, Greenbox's pride won over, having been too fascinated at the results of his own work. What made him REALLY crazy was his interfacing with Zed. Given the level of integration he had with Zed and the machinery around him, it's possible that Zed's influence, itself tainted because of the Metallikats' influence on his programming, corrupted Greenbox further.
The SWAT-Kats arsenal makes a lot of sense when you realize:
The Enforcers wouldn't be stupid enough to throw away live ammo.
The reason Feral is such a By The Book officer is possibly because he remembers that the one time (that we know of) he broke the rules by interfering with his subordinates in apprehending a suspect led to the Enforcer building being damaged and him having to kick two promising (if somewhat reckless) officers off the force. The Fridge kicks in even more in that said officers go on to become the SWAT Kats and act as foils to his methodology.
While the Swat Kats dropping Morbulus into the bay backfired, and they blame Feral when it's their fault, they likely believed that the fall would leave Morbulus too injured to escape, and the life jacket in his suit would keep him above water. This is supported by T-Bone referring to Morbulus as "gift wrapped" a Feral voicing the chance that Morbulus drowned after the fall. The Swat Kats just didn't anticipate that Morbulus was that durable.
Its also probably due to T-Bone and Razor being bitter against him having been once Enforcers who got kicked out by Feral intentionally hitting their plane that cause a crash on headquarters although T-Bone heavily implies that this isn't the first time Feral make these blunders and they had to clean up for him and Miss Briggs who had to supervise all of Enforcer activities probably notice these blunders even after Feral became By The Book.
Dark Kat, Dr. Viper and the Metallikats have some genuine credibility to their survival after the explosion rigged by Dark Kat.
Dr Viper being part reptile would probably regenerate from such incidents.
The Metallikats are near invulnerable machines who only got really damaged when hitting from the upper atmosphere.
If anything by his theme, Dark Kat's excuse is that he has supernatural abilities to escape.
The evil Miss Briggs could have been informed that there are two set of Swat Kats but since she ally herself with Dark Kat who if anything like his Prime counterpart might have already planned on betraying her.
In "Chaos in Crystal", after Rex Shard is defeated and made normal again, everything he turned to crystal reverts to its normal state. Consider the warden he turned to crystal... and then shattered. That would've turned into one messy office.
Every single kat skeleton we see (and we see plenty of them) has a skull complete with ears.
Why did Professor Hackle, the brilliant cybernetics scientist, think that two random (dead) strangers would be psyched about being turned into a robotic Maid and a robotic Chauffeur? Sure, he had no way of knowing they were dangerous criminals when they were alive (except that his island home shares the bay with a maximum security prison), but he just assumed they would be leap at the chance to spend their new lives (with new, shiny, super-strong and durable bodies) as household servants.
There's quite a bit of fridge logic at work when it comes to the Metallikats, because his plan to make them his maid and chauffeur came after he knew they were Mac and Molly Mange. He seemed to understand the second time that they couldn't be fixed, at least. And then there's the whole question of leaving your freshly-activated, highly experimental robots in the same room that you keep your experimental weaponry and heavily-armed hovercar. Hackle shows an incredible amount of Genre Blindness.