Yup! Definitely part of the learning process - I see it as an opportunity to study your own test taking, and don't read into it unless it actually becomes a pattern.
Congratulations on the top school with money! I'd go ahead and send those e-mails - I can't think of any circumstances in which a brief thank you note would hurt. Unless, of course you actually do say "I think you're yummy!" ;-p
Depending on my work plans (that should be determined in a month or so), I'd be interested in leading the September BR group, unless there already is one or is someone far more qualified to lead it! Just throwing it out there.