I'm afraid that I can't help with the identifications you need beyond opining that the plant in the last picture is probably not a true cactus, but some kind of euphorbia.
I noticed that you haven't yet gotten any responses, so I would like to offer a friendly tip which might get you a better response to your request for help than you've gotten so far. You should break up your request to one plant at a time, i.e. one plant per 'thread'. That's simply to make it easier for anyone who does respond to identify which plant is under discussion, and for anyone reading the thread to do so as well. Several pictures of the same plant in a thread are fine. The more the better for helping with an identification. But just one plant per thread. I suggest you resubmit your plant photos, broken up by individual plants, and see if anyone is willing, then, to offer help.
Good luck finding out what your mystery plants are.
