I’ll take a crack at the “no money in Star Trek” argument.
Thing is, in Star Trek you have replicators that can produce literally anything. Food, clothing, consumer goods, anything except living beings.
But a transporter (which is really an upgraded replicator) could be used to living things, we see it happen several times by accident in the Star Trek universe. How many copies of Kirk or Riker do you need? If you can do it once by accident, with a little research you can do it on an industrial scale. But nevermind that, ethics, blah blah blah.
Back to the replicators themselves. What does it mean when you live in a society where you can have any object you wish at the punch of a button? All you need is a pattern and you can have a duplicate of the crown jewels, you can have a 12 course gourmet meal, you can have books, you can have fine art, you can have ANYTHING. Just push a button and out it comes. And you have ubiquitous communication, ubiqutious computing, travel anywhere on earth as easily as punching a button.
Now do you see why there’s not much use for “money” in the Federation? Of course there are some things that can’t come out of a replicator, like any skilled personal services, land, “original” objects, handmade goods, latinum, maybe the replicators on earth won’t let you order a phaser or certain mind control devices.
Everyone’s basic human needs for food and shelter are taken care of via replicator for free. Everyone has access to just about any entertainment they could imagine, for free. Anyone can travel anywhere on earth for free. Any toy or piece of equipment you can imagine is provided free. So what jobs can most people DO? For most people any “job” they have is really a hobby, they only do it because they like to. So if you have a restaurant (like Sisko’s father) you can’t make any money, you just have a restaurant because you LIKE having a restaurant, and farmers supply you with real unreplicated ingredients because they want someone to appreciate and eat what they grow, and people go to the restaurant just because they feel like it. A gift economy makes sense, because every good or service anyone can produce is by definition a luxury good, absolutely no one really needs anything anyone can produce.
It’s my theory that “Star Fleet” isn’t really part of the Earth’s government. There really is no earth government. Star Fleet is just a club for eccentrics who like to build and play with spaceships, and they have certain traditions they like to observe. You could build your own spaceship from a replicator and fly around the universe with it yourself, except it’s kind of dangerous if you don’t know what you’re doing, and it’s more fun to do it with your friends.