On the main GIMP window, another tool could be added that contains some of the most commonly used things, as preferred by the user such as clear, copy, paste, merge down, autocrop, 3 to 5 different brushes, color to alpha, alpha to selection, blur, and whatever else the user would like as "common".  This way, they're just one quick click away, especially those that don't have keyboard shortcuts (like copy/paste or clear would).  GIMP has 29 tool icons and by selecting this 30th one, the tool options show the commonly used things, as clickable icons (or, if no icons are present, a clickable button).