I must admit I have no clue what type of plant it is. It didn't look like a cactus to me, but I don't know much about flora so I can't tell.
Probably not. As you say, it's too far south and I never heard about any "use" of Peyote in this area at all. If there are "followers of the Peyote" around, they are usually quite vocal about it. :-)