Here, as you bolded, people see increased demand, and so increase production to meet that demand and to therefore profit from it, that is a standard economic principle. But the minimum income idea is reversed. With the minimum income idea you are adding money to the system without the prerequisite work. To put it another way, some people may do some work (earning crypto) to give to everyone. But that work at earning crypto comes at the expense of any and all other productive work that those people could have done, so the net result is no real change. They are just earning something of value, which is the same as if they earn dollars, mine copper, mine gold, or mine bitcoins.
The standard capitalism approach isn't going to change one scintilla nor will basic economics be flipped on its head because these things ARE simple capitalism and simple basic economics. Nothing that has been suggested here changes the simple economic principles involved: people respond to incentives, or given a choice of two exactly equal things, people will always choose the cheapest one for them.
3D printing is no different. It just means that for some items it will become cheaper to home-produce them than it is to buy them already factory made. Trekkie utopia fails because not everyone will do as Picard says. I certainly won't, and neither will anyone that thinks as I do. That doesn't prevent you from doing it, have at it. It means that I will not participate and will deal with Trekkies as I see fit. I will be the Big Pharma that Cuba (the Trekkies) buys its drugs from.
Certainly, over time, some things become cheaper given reductions in the amount of labor and capital used to produce them. Conversely, other things become more expensive as the reverse is true, given the scarcity of all resources. But what you said above isn't an improvement on capitalism, it IS capitalism, because the economic principles remain the same. There may just come a time where most basic necessities are very very cheap, but that is directly a result of simple economics and capitalism, not some perceived sea change in how labor is used or because some people donate their money to everyone else, no matter what the form that donation takes, labor, dollars, bitcoins, litecoins, diamonds, or whatever.