Nearly there!! I've decided to leave Thing 19 till the end and to reflect on everything I've done once I've finished.
As for Thing 22 - I haven't done any volunteering as part of my career so can't really comment on it except that to me it seems to be a great way of getting experience and adding to your CV while waiting for the right opportunity for a paid job to come along. As long as volunteers don't replace existing staff as a cost cutting exercise then I don't see them as devaluing professionalism as the volunteer is learning from the professional and it gives permanent staff an opportunity to exercise their training and mentoring skills.
Thing 20 I'll look at tomorrow hopefully. My Cv is in dire need of revising and though I'm not currently seeking another job it does pay to be prepared.