2.1 - Strangely enough, you can take a poorly printed machine and tune it to print a set of parts much nicer than its own. It seems counter intuitive, and certainly a well made machine can be set up to print crappy parts, but as it stands it's not as big a problem as you might think. Alternatively, a universal constructor might not be a 3D printer, as it were......
2.2 - What do you think about that idea?
2.3 - You're the first person (so far) who's pointed out the art aspect, but I think it's a big one. There's still a degree of craftsmanship involved in making really neat 3D printed objects, and so I see it as still more of a 'black art' than one might like for commercial purposes.