High Sierra? Did you install the patch that was released last week? I know the supplemental update fixed a cursor issue in InDesign.
I believe so! Probably on Apple's end than rather than Adobe/ours?
It's hard to say. It's been big issue on the InDesign forum, but this is the first I've heard of it on Photoshop. You could do the standard next step of resetting preferences, but if it comes back, I'd recommend reporting it.