Regarding Finch-Fletchley and Weasley, I think that's an excellent idea. They're both exceptional, especially considering their age and the standards that too often held sway at Hogwarts. Marvolo would also be a fine choice, should Our Lord wish to see how His son measures up.

I'm sure Miss Greengrass will do a fine job expressing welcome. For all our sakes, it may be best if Mr Moon understands his role there to be purely decorative.