I would like something along what 3D apps offer which in this case is a more intuitive method of making advanced shapes. For the sake of keeping it simple will stick with only 2D results.
Will start with a history mode for shapes to be able to make changes interactively to any setting without losing forward changes.
For example you have the extrude tool which drags the edge and makes another adjacent polygon. You also have the inset tool which makes an inner or outer copy(yes you could copy the shape and scale it down manually but then you would loose the history mode). Or the add loop tool which adds a subdivision across a loop or ring edges (3D terminology). Or the bridge tool which let's you bridge 2 edges, add more subdivisions and influence shape. Then you also have the array tool(sometimes called a clone tool) either linear or circular. You also have the weld and merge tools which allows you to interactively merge points. And there are others that could be mentioned.
Just some ideas :)