ie. I need two circles, one with 26 nodes evenly spaced and the other with 30 - a walk in the park if I were using a CAD package
It's possible if a little fiddly (at least in X7, but if I remember correctly this should work in X5 as well).
1. Draw a circle.
2. From the Circle toolbar select the Pie tool and set the degrees to 12 (for 30 segments)
3. Click the pie section twice to change the object to 'rotate' mode and move the point of rotation to the apex of the pie (the centre of the circle). Have 'snap to object' on to make sure this is exact.
4. Change the Pie mode on the Circle toolbar to Arc.
5. Rotate the object about its centre by grabbing one of the nodes until it snaps to the next node point and click the right mouse button to duplicate the object. (You can do the same by duplicating the object (Ctrl-D) with 0 offset and then rotating the duplicate by 12° via the dialog on the toolbar).
6. Press Ctrl-R 28 times (in this example) to complete the circle.
7. Select all objects and Combine (Ctrl+L) if you need a single object and combine the node pairs if you need single node points.
30pointCircle.cdr