It's going to be a while before my character can use it, but thinking ahead re: project image, imagine the following scenario:
I cast invisibility on myself. I follow it with project image. I then cast another invisibility spell on the projected image (which is ok since invisibility is another illusion spell. I then cast offensive spells through the image. Question: obviously the image loses its invisibility. What about me, the original caster? Am I now visible?
Hmm, that sounds right to me too. I suppose the thing to do is cast Greater invisibility on oneself and then let the projected image rip away while one stayed out of sight. I suppose if one stayed far enough away from the image, you could even stay out of the range of a true seeing spell and still barrage someone with close range spells!
Yup. Those two have the right of it. :)