I think that you, the Professor, and the Lauderdale are probably the most sensible people on this board, An. It's a good idea.
"for us to play the originals characters. I don't think it's very fair for one person to play all those chars. Besides I wanna be Harry"
Sierra, hogging all the "good characters" isn't really the objective here. What if, say, Ariel or someone else also wanted to play Harry? There'd be a big fuss, and at least one person would end up hurt. This way, the GMs will start out the plot, get it moving, perhaps set a bit of a reference for playing certain characters IC. Then whoever wants to play them can apply for it.
This may be my perfectionist's soul talking, and anyone can feel free to overrule me, but I feel there should be a small test, maybe a little one-paragraph thing written in the character of the original an applicant wants to play. But we don't want any hurt feelings, so it may not be that good an idea.