how to make ovals out of polygons?

I am familiar with the circularize function to make circles out of polygons.
What I am looking for is how to make ovals out of polygons. Is there any way of doing this?
My favorite way to circularize is to draw one axis line. Then duplicate it and paste it exactly over the original. Then rotate the duplicate line by 90 degrees. You then have two axis lines intersecting at their centers. You can now connect the axis endpoints and use the square function to make sure everything is “square”. Then circularize it. I use this method for drawing circular pools and water towers.
A side question: Is there any way of telling the editor how many points to use when circularizing? IOW, instead of the standard number of points drawn, I would like to be able to define more or less points on the circle. I would also like to be able to draw simple arcs instead of a whole circle then deleting what I don’t need.
P.S. I am using the standard editor.