First off, I have killed more anemones, that I would like to mention. 2 of them that died, died the day after I moved them. When I would say they were dead, they would shrink up to about 1/4 of there original size, look like they turned inside out, and were rock hard with a mucasy film around them. I think that is safe to say dead. In my opinion, I would only move it as a very last resort. The bad thing is, when you move it, it is going to move itself where it want to be. What you might try to do is see if you can slide a small flat piece of rock by it (in the direction it is moving), and hope that it climbs on to that. Mushrooms typically like less light and current than anemones. Are your mushrooms up high in the tank near the light? If this is the case, maybe you should (when the anemone leaves the rock) move the shrooms.