I don't think all the armor designs are in, as all robes and any item with a blue shirt icon is basically like wearing nothing.
The only island thing I remember in the cave was when you pulled a certain lever and was teleported there. I had unchained my mains from my companions and was able to just use teleporter pyramid to get back. Or use the homestead button. But I was able to leave from the cave the same way I entered.
