1. Absolutely. Stay WAY away from Chinese, and some other Eastern, horns. They are simply horrible. They are cheap knockoffs of American brands, and they just don't perform. Except for one: Shires now has a horn made in China that is modeled after the Edwards line. (As far as I understand anyway...)
2. .525 bore horns actually have a great use in the orchestral world. Quite often a large bore .547 horn is just too big and puts out too powerful a sound for what is appropriate. I play an Edwards, and I have found a few pieces where it was just too large for the job. Kinda like trying to mow your lawn with an AWESOME..... chainsaw. I am currently looking for a good Bach 36 (keyword: good... I'll be looking for a while) that I can use for those pieces in particular that I want a smaller, brighter, more mellow sound, that I don't want to use an alto for.
Like everyone else I have gone nuts comparing brands and models. The basic truth is that it is the person holding the horn that makes the most difference. But after getting past that issue I have a like for old horns. The quality seemed to die for many horns about 1970. We went through an electric guitar era in which all that seemed to matter were electric guitars. Now brass is in and brass rules! To me I'd rather find a good Conn, Olds, King or Getzen from about 1960 and pump a few bucks into it and go from there. And I do not like lite weights horns. A bit of thickness in the brass goes a long way towards having an instrument that will last a lifetime or more. A hard six hour gig may get a man a bit arm weary but what the heck. Musicians have to suffer a bit just like all other trades. At least we don't have to dance on the tips of our toes all night.