I'm pretty sure stimpacks are just morphine renamed. Which means they come from poppies.
A healing chem. When injected, the chem provides immediate healing of minor wounds.
-Description of Stimpaks in Fallout 1.
Plus there is an entire piece of cut FO2 dialogue explaining that Stimpaks can actually cause skin to regrow around wounds.
It is essentially supposed to be a super-drug designed for rapid regeneration.
Morphine does also exist in the Fallout Universe, but because some countries like Australia have strong censorship laws it's refered to as Med-X(It gives a bonus to damage resistance, is highly addictive, and is used by the Followers to numb pain, making it functionally similar to Morphine.
Megaton has farms, we just can't see them because the game world has limitations
Not good enough.
Almost every single settlement in Fallout 1 and 2 had either Brahmin or Crops despite engine limitations.
Almost every single New Vegas settlement had Crops and some kind of Livestock despite engine limitations.
The Pre-War govermment having CIT experiment with FEV makes perfect sense as they have been obsessed with this stuff for a very long time.
Files in West-Tek state that all FEV research was sent to Mariposa. The project was top secret, so it's unlikely CIT would even know about it, and even if they did, it wouldn't have been shipped to them without West-Tek knowing first.
Feral Ghouls are something which makes perfect sense given GHOULS ARE PEOPLE SUFFERING RADIATION POISONING. The idea their brains might decay as a result of old age or radiation iis fine by me.
If there brains are rotting, they should be going delusional, perhaps lashing out at people coming too close, not turning in to literal cliched zombies.
And Ghouls might not have been suffering from radiation poisoning before Bethesda came along. The most commonly accepted explanation was Airborne FEV virus.
So, when one of the complaints is the world never rebuilds in 200 years, you have the complaint someone organizes people to rebuild?
The world should be rebuilding by itself within time, and each individual settlement should have there own identity. It shouldn't be a matter of "Everything remains stagnant for a couple hundred years, then one guy from 200 years ago wakes up, suddenly becomes the king of everything and unites the entire world under one banner", that just seems like a stupid way of feeding the power fantasy players might have, rather than actually being bothered to create a world that could plausibly exist without the player.
I imagine they're very much aware they have a reserved place in Space or on the Poseidon Oil Rig
A. Sure, because the Enclave is just going to let two generic mooks, whose sole contribution to there cause is guarding a vault right on to the Oil Rig. That's definitely how a top-secret elitist society would work.
B. They are on the other side of the country. It's going to be a long trip to the Oil Rig, and I'm guessing planes wouldn't work too well from all the Electro-Magnetic Pulses. By the time they reach the Oil Rig, they'd already have seen most of the dangers of the wasteland anyway, and would also be too mutated to be let in.
This is explained in Kellog's memories that he was ordered to murder them all except for the spare
The Institute needs pre-war DNA for an experiment. There is a Vault filled with a dozen residents of pre-war DNA.
The Institute is choosing here between having 11 backup test subjects, or killing a bunch of people for no valid reason. I wonder what any rational group of people would choose to do in that scenario?
The Gunners are Vault-Dwellers trained in actual military tactics and equipment
Since the game isn't courteous enough to actually allow you to talk to Gunners and ask there backstory(Like pretty much any other Fallout game would have), there is no possible way of confirming this.
There is no evidence for this and it is 100% speculation.