Pages for better Login and Create Profile Sequence
This is a proposal for a solution to UsabilityObservation/User confused by preferences on first login.
Different Pages for Different Actions
By creating these four different pages all actions would be nicely separated. Moreover, if these are actual wiki pages, administrators can supply additional information that applies to their wiki only.
The complicated bit (and the one where MoinMoin currently performs badly from a usability POV) is this: Hitting "Create Profile" on /CreateNewProfile redirects you to your user page which displays /WelcomeNewUser (since the page does not exist yet).