Very good topic. This link covers some of your questions. It is not about swords but the same argument applies. Many fine words about good new art as opposed to bad new art, and who is to say who can make art {no different to swords} These comments all seem to be from collector dealers or dealer collectors????
http://www.newguineaart.com/png-art.php
Something I would add from my own experience: try selling or exchanging a good new piece to a dealer, sadly their opinions I have found are somewhat different to the fine words.
If you have the money to collect fine new pieces as in this other link then fine. If you have not you probably get better pieces and value from old to antique. Not only do you get a nice thing at sometimes sensible prices but also history. I know where my interest is.
https://www.youtube.com/watch?v=2x5WzIu5iXU
A really good documentery understanding modern sword collecting.