Apparently some of the plants are added by TTW. My fault, I thought I removed any relevant mods but this is TTW Fallout 3 so its tweaked.
Timestamps in description!

republic of dave next question

Another thing about Big Town is that if you save the town, you can encounter a scavenger in the wasteland with a brahmin and a dog/yao guai who says he is on his way to Big Town. When he arrives, he stays there permanently, giving the town another trader, and some extra defense coming from the scavenger and his pet.

And in Canterbury Commons, if you recruit Sergeant RL-3 as a companion at the RobCo factory and then dismiss him, he will travel to the town and guard its entrance, adding further protection.

Though all of this relies on the Lone Wanderer's actions.

An hour-long logistical analysis of the real-life translated pros and cons of an open world video game from 2008? If this doesn't activate my neurons, I don't know what does.

I love living here in Tranquility Lane, I just can’t seem to remember when I moved here!? It’ll come to me one day. My neighbors are a little strange though. Especially Betty. We don’t talk about Betty…

If my fat ass walked into Andalle it would be Christmas and Nuclear New Years all at once for them 💀

For Canterbury Commons, I find it surprising you don’t mention the possibility of negotiating with the Mechanist and the Antagonizer. Considering she is so easily swayed to turn good, and the Mechanist is so amazingly gifted with robots, imagine the defensive value of making them a super hero duo. Imagine if she could get control of the fire breathing ants. He could be a massive help with infrastructure. Clearing that rubble would be a lot fucking easier with some construction capable bots.

There’s so much that could be done with their aid.

My theory is that everyone knows little lamplight is relatively safe so people who can't afford another mouth to feed, don't want a kid, or for whatever other reason can't raise a kid they bring them to little lamplight for them to raise them. This would also explain why there's so few kids in general in all the other towns.

Headcanon about Little Lamplight's stable population.

Big Town wasn't always this place teetering on destruction. It had teens and adults living in it, even elders, once abd was a bustling town. Children were born buy these children were kept safe from the wasteland by going to Little Lamplight. The cycle thus repeats itself with every generation going back to that first generation of kids who lived in Little Lamplight after the bombs fell during their field trip.

The reason  Big Town is so miserable now is a super mutant raid sometime in the recent past killed or drove off everyone in town and the current crop of residents are those who recently matured out of Little Lamplight only to find Big Town abandoned.

It's just headcanon though pieced together from context and speculation.

all of these towns have an open position of cleaner

Just a heads-up on the "where did they go?" Arefu question, Evan King tells you they all dismantled their shacks and moved on. So they literally just brought their houses with them, lol

I think you're way too positive about the Mechanist and the Antagonizer's effect on Canterbury. The townsfolk say that the Mechanists robots are an active threat and do way too much damage whenever they fight off the Antagonizer. Expecting the town to build up their defenses while battles that destroy their town are constantly happening isn't a realistic option. At best, the Superhero Gambit should be a net neutral to the town rather than an asset for defense, at least as long as the Mechanist is a factor. Sure they keep raiders and other dangers away, but they themselves are destroying the town.

A bit more context about Andale:

Old Man Harris is the father of both Linda Smith and Martha Wilson (she lets it slip when chatting with her), making him the grandfather of both Junior Smith and Jenny Wilson, hence why he adopts them if you kill the adults of the town. That’s part of the in-breeding that was going on in the town.

I don’t think Old Man Harris’ wife, Gladys, was eaten, but simply died out of old age, given that she was also the mother of both Linda and Martha.

Anyway, a couple more things to mention:

1- Free daily strange meat pie if you decide to not judge their cannibalism… or if you are a cannibal yourself, so… free food!

2- Using console commands to revive the corpses in their “workshops” turns them into adults… with dialogue lines from Little Lamplight children, which aren’t said by any other adults in the game, which seems like a subtle hint about the basis of their diet being Little Lamplighters that come of age, get lost on their way to Big Town and end up in Andale.

Edit: Forgot to mention that Old Man Harris was a cannibal himself, but once his wife died, he began doubting his cannibal lifestyle, resulting in him warning people coming to the town.

Just to make Andale slightly worse, that mutfruit plant isn't actually there (or anywhere else) in an unmodded FO3.

Paradise falls is a nice play to live I hear

another point in Rivet Cities favor. respatory issues are pretty minor when you consider what other illnesses you could get out in the wasteland.

as any random shack could get some pretty big issues with radiation. and while Rivet City no doubt has some issues with that. id suspect the aircraft carrier's hull provides at least some protection from that. at least more then what the rest of the wasteland gets.

also its well protected from the weather. a big storm hits the capital wasteland? Rivet City won't really care. while a smaller settlement would likely have major issues.

Regarding your comment about doctors, I’d study the history of settlement in the 1600s where doctors were rare, and settlements were formed more around resources and transport routs. Basically settlement tended to spread faster than new doctors could be trained.

The kids at Lamplight are well aware of the super mutants. They have a barricade across the one tunnel to Vault 87 that is manned by an armed kid at all times. It's very similar to the entrance in that respect. They closely guard both paths into the caverns.

One thing that could be interesting to discuss is how it IS a player being sent there. We have information Elder Lyons would kill for. That Super Mutants aren’t made in downtown, but in Vault 87. Additionally, we know the Enclave is at Raven Rock. A deal could almost certainly be made. “Put a brief pause in your Good Fight to clear a small base of them and I’ll tell you exactly where your two mortal enemies are.” Is one hell of a bargain to get them to clear the Germantown PD.

Hey if you’re a woman you can always move in with Ronald in Girdershade, he seems very accommodating about that for some reason.