If I have a creature who is blinking with a ghost touch weapon, does this mean the 20% miss chance I have to hit no longer applies?
I'm afraid not - ghost touch lets you hit incorporeal, and lets incorporeal pick it up and wield it. With blink you are going ethereal, which is not exactly the same thing. You are incorporeal when you are ethereal, but being ethereal you can't attack anything material (as per blink: "An ethereal creature can't attack material creatures, and spells you cast while ethereal affect only other ethereal things.")
Nice idea though :)