Several bright followers reutrn in at least one ending for NV, so no, they live.

Vault Mechanic is a guy like Stanley, not exactly someone qualified to work on space age rocketry.

Wait? You can use those mini rockets. I don't remember that being an option.

You need five of them, and you need one in your inventory when you speak to Chris Haversam.

It's optional to use the five rocket things, I just always go for the dead guy in the anti-radiation suit, it's a lot easier and makes more sense.

Except the place feels as empty and lifeless as any other town in the game, around 12 people and 2 caravanners who usually get killed by vipers once they leave, that is if the legion didn't kill them beforehand. Most Fallout 3 towns were interior cells and could inhabit more people. Here's hoping for a touch more life in the 4th instalment.

Actually, I'm pretty sure that most Fallout 3 settlements had way less people than NV.

Technical limitations are why everything is as small as it is, this is incredibly obvious when looking at New Vegas concept art:

http://fallout.wikia.com/wiki/File:Conceptart-thestrip-B.jpg

http://fallout.wikia.com/wiki/File:FNV_concept_art_Vegas_Skyline.jpg

It's supposed to be a sprawling city, just as the rest of the towns are probably supposed to have at least a few hundred people each. What we get in game is essentially a representation of what the world there is like.

Just like in the Vaults that we see. They were meant to have up to 1000 people, but we never see any number approaching that.