I'm beginning to think that this installation of Docker has some sort of caching that they are not telling us about. This means that some things just take awhile. When I first checked @adam profile was definitely 404. Now it seems to work. I did nothing other than wait for it.
I just added custom fields to everyone's profile where you can put your Twitter, Steam, and Battle.net IDs. They didn't actually show up until minutes after I added them.
If anyone has suggestions for other fields I should add, let me know. These fields also appear on the registration form, but are not required. They will appear on your public profile if you set them.
I also added the field for "reason for joining this forum". Unlike the other fields, this is required on registration. However, because Discourse is stupid, it's also required you put something there if you edit your profile. Don't worry, that field is not visible on your public profile like the others. Just put whatever.
New users on the registration form should obviously put something in that field that lets me know they are a real person wishing to join the community, and not some bot.