Using Orchard Core, is it possible to add fields to a User?
For example the company they're from, or some sort of preferences?
And then allow the user to change some of them, while keeping others read-only or hidden?
I don't know how to allow the end user to EDIT the fields yet, but I figured out how to add custom fields to the users...
Add a new content type and give it the stereotype "CustomUserSettings" - turn off all the Creatable, Listable, Draftable, Versionable, and Securable options too.
Then you can add all your fields to this content type and they will display in a tab on the user page (tab is titled what you named your content type) I named mine "User Settings"...