the diameter of the moon is one fourth of the earth
however its volume is about one fiftieth of the earth
our knowledge of the size of stars is of course indirect and based on numerous unproven assumptions of the methodology of measurement, and of course old assumptions are often replaced by newer ones (the old ones are usually laughed at). if one has faith in our indirect “measurement” of something trillions and trillions and trillions of miles away, your argument is weak to anyone who is nor enamored by Scientism.
your third point seems valid at this point