Does this also mean you can't edit things that are presumably on your profile (i.e. your introduction or something) or am I just that obtuse that I can't find it?
you still can edit the items that are visible on your profile. The majority of items are in the bottom half of the settings section "My Info" [see screenshot below], while the Hanko can be created/managed under Games->Hanko. If you cannot see these options you might need to tick the "Advanced settings" box in the top right of the settings pages.
...I am obtuse because I've been in that screen at least 5 times (either looking for profile things or passing by it while editing other stuff) and never noticed that. WOW.