4 - I...somewhat disagree. I spent a few weeks looking into current and future 3d printing tech, and outside of some
very limited use-cases would I consider that the output quality and materials mix from any 3d printing tech to be a threat to traditional manufacturing.
It's a nice idea, but it's just very very far away from happening.
Even relatively simple items right now are not something that are even close to being duplicable in any current or emerging 3d printing tech.
For example, there is nothing on the horizon that will enable me to 3d print the equivalent of a working $5 104-key keyboard.
Now if I want to buy all the electronics and internals and spend a few hours printing and assembling a custom keyboard (because my time is free right?) then yeah, I might be able to 3d print something of use.
I'm actually looking around my office now and every thing I see fits into 1 of two categories
a) Not feasible to 3d print the item e.g. a keyboard
b) Cheaper to buy it and get it some other way e.g. the red Solo cup I'm drinking some water out of