The climax of Transformers One isn't 'killing is wrong' it's 'The future shouldn't be built on an execution', Optimus agreed that Sentinel needed to be punished, but he wanted it to be done properly, fairly so the people could see that the revolution was for the better, whereas Megatron demanded his blood now

My love for complex war stories is at odds with my desire for cool robot fight.

I love your ending line, by the way "Just because you have sympathy for the devil, that doesn't mean he stops being the devil."

....Optimus never explicitly says he doesn't want Sentinel to die. He says that he doesn't want to START the revolution with an execution

I remember, when I was around 7 years old, reading a comic in Transformers Prime magazine about Optimus Prime and a random Vehicon being stuck at a swamp, where they helped each other get out of it. When they got out, they knew, that the next time they meet each other they will not be on the same side. It isn't an unusual plot, but, back then, for me it was, probably, the first time seeing this trope.

So I think a key point people miss about TFONE is that I don’t think Orion doesn’t want Sentinel to die, he just doesn’t want D-16 to execute him… publicly… without a trial! If I have one problem with that movie, I think some slight dialogue tweaks between Orion and Elita would have helped. Have Orion suggest a trial. Or just that it would be overly cruel to kill him. Something that tells the audience that Orion agrees that Sentinel needs to be dealt with, but that D-16 is doing it in a way that will just lead to further escalation and destruction! The movie does a good job of demonstrating that Orion hasn’t quite mastered the whole speech thing yet, so it’s entirely believable to me that he would screw it up when it matters most and turn D against him when D-16 is at his most vulnerable point.

Unicron's presence being the sole reason the Autobots and Decepticons could actually offline one another is really interesting. He is truly the Devil of this fiction.

Even the vehicons of transformers prime feel like people, even if they're sparkless bots.

The thing about writing a villainous or antagonistic faction or site in a conflict is on the one hand it can be dehumanising to paint them all as generic faceless evildoers, but on the other hand it can be problematic to have them be too understandable in their motivations and such -- sympathy for the devil, as you say, can lead to "the bad guy was right actually" mentality and muddy the message of the story, and in media aimed primarily at children, who are pretty impressionable, it's particularly tricky to do all that while also making something the networks will air and parents are going to approve of kids watching... well, when the parents care of pay attention to that, but, y'know. Transformers did a pretty good job at making charismatic and unique villains who are also clearly villains, so people could love them as characters while also still recognising they're the bad guys.
The redemption arc, villains changing sides, is also one of those things that some shows do poorly and others do well. When done well it can be a message of "it's never too late to improve yourself and do what's right" or "sometimes people can seem bad but are capable of change", etc, while other times it can seem like it's saying "any amount of evil can be forgiven if you have a tragic enough backstory or decide to be nice one day" kinda thing.
I think when it comes down to it, there's also a part of our human nature that wants to see a spark of life and humanity in anything, imparting personalities to our toys, humanising our pets, even imagining two raindrops on a window are racing eachother, and maybe part of this tendency to want to imagine more to throwaway characters is just from that natural tendency to animism and anthropomorphism we have.

First point: like others have stated, Orion probably wanted Sentinel dead too, just not via extrajudicial murder. I'd like to make the parallel that usurping the current leaders' power through violent murder was D-16's goal and exactly what Sentinel did to the primes. My personal interpretation is that Orion was thinking about the long-term consequences, while D-16 was hyperfixated on personal revenge.
Second point: The G1 continuity did have death before the '86 movie. It's how the matrix of leadership even had a lineage to begin with.

The transformers comic on the backstory of Megatron is my favorite of all time. The moment when he stands in the field of all the brothers Bots he killed really hit hard. I cried multiple times reading it.

Shit hits hard

Problem with "generic storm trooper" transformers is it goes against the subtle theme of "each robot has an identity". They were robots, but they ALSO had unique personalities.

One of the things about the Decepticons that makes them different is that they're not evil characters who were made into toys, they were toys who were made into evil characters. Hasbro bought the rights to pre-existing transforming toys from Japan and then hired Marvel to write a story about them, and Marvel just picked out the ones that looked more or less evil

Orion stopped D-16 because he knew if he killed Sentinel then, he would lose himself in his rage and hate. And whatever replaced Sentinel's government would be just as unjust, corrupt, and needlessly violent

3:19 My theory is that Cyclonus is a mix of both Skywarp and Bombshell.
Bombshell’s intelligence mixed with Skywarp’s loyalty.

You do realize that's the whole point—that the Vehicons from Beast Machines are a soulless army, right?
They are the exact opposite of an ordinary soldier who has a personality, and that’s what makes them so terrifying.

8:05 I cannot believe you were able to say that without laughing

25:00 Damn... That can explain why the "war" lasted for millions of years without any sides truly winning nor being hunted down to extinctions. They were "sports teams" playing war games.

Good video, and unlike other commenters I really like your interpretation of G1 being a "playfight war". I think people are too quick to dismiss it.

This interpretation allows for the idea that nobody dies in the show for a reason and why they do in the movie. I also think it's effective at explaining why the deaths in the movie were so impactful. You spent 2 season coming to know characters on both sides, seeing them fight and yet also seeing them come back next episode. This helped viewers feel that they really got to know the bots, on both sides.

When people die for real in the movie, you feel that, even for characters that didn't have much screen time in the show. And I think that is because if they at least had a toy or a cool design, they had something a viewer could attach too. So seeing any bot die in that movie felt more poignant than mooks in other movies.

This is also helped by there not being a uniform to either side, there is no faceless soldier or stormtrooper, so to say.

"imagine if there was a whole continuity where the Decepticons are the good guys and the Autobots are evil."

Shattered Glass exists and do research.