These, and most of the alleged anachronisms for that matter, largely depend on one's assumption of the "tightness" of the translation. Conversion of concepts across languages is not always precise (as anyone who's learned a foreign language can attest). Is there no room in your reading of the book for the notion that these "words" were simply the best available descriptors?
The metallurgy problem cannot be erased by invoking loose translation. There were supposed metal artifacts seen by witnesses, and part of the process of metallurgy is actually described in the text.
Horses are a problem because there is no "animal X" that can fit the context of the Book of Mormon. see: tapir