Ceramic Glaze Tests - Raw Fired vs "Double Fired" vs Regular

I show a series of test bottles subjected to three different firings on two different glazes. Firings were done at Cone 05 and Cone 5 in an electric (oxidation) kiln.
I want to know two things:
1. How does raw firing effect glaze color?
2. Can I under-fire a glaze, damaging it with crazing, and then re-fire to "heal" the glaze?
Please leave me a comment if you have thoughts, want to share your experience, or are inspired to try something new.
Enjoy.