That makes sense about the little loops; they were confusing me. Generally you’re going to see some kind of horizontal seam on Navajo beads. I don’t know as much about Mexican beads, but they seem to often have no seam or a vertical one. But of course there’s always exceptions, so a closer up picture of the beads when you can take one would be helpful. It can be confusing! I included a link to a discussion we had on this topic a while ago.
Beads/Navajo Pearls
The issue is that without a hallmark and no provenance from a good store, it’s hard to say to say for sure something is Native made. I have quite a few pieces of Native American jewelry that don’t have a hallmark, because they’re a little bit older, but I bought them in trustworthy stores in the Southwest that knew what they were selling.
Squash blossoms aren’t really my thing (mostly because like you said they’re quite expensive, and I know that I prob would not wear one as much as other things) so I’m really hoping someone else will jump in to give you better insight! And your squash is pretty whatever the case!