Comment/note is extremely helpful especially for those collapsable actions such as "Group" action. As you see from the screenshot, when collapsed, it shows nothing. It will be great if we can show the notes from "set note" after "Group". For now, my workaround is adding a comment action above the "Group" action.
Yes, you can. I do it myself all the time. Just click the gear icon and choose the “rename” option. Your workaround is good for longer comments & notes, though