For ages when I train InDesign, I always get the question - once you have created a star or polygon within InDesign, can you change the number of sides/points afterwards. Each time I would tell the trainee - no. I have never seen any documentation, notes, tips, etc that tell me this was possible.
However, I was playing around InDesign a couple of days ago, creating polygons, and I suddenly thought - what if i draw the shape, double-click on the polygon tool and change the number of sides, whilst my shape is still selected? Voilá - InDesign CS4 lets me change the the shape after its creation - it is possible to change the shapes in InDesign CS4 after they have been created.
If you have an older copy of InDesign, just try and see what happens, I only have InDesign CS4 installed so I do not know what any of the older versions will do. Try it and see!