We have a very simple SharePoint Server 2010 SP1 installation. We created and configured everything manually, and only set up what we really needed. So there is no user profile service in SP, and we only use Windows authentication, no claims, no forms. We only have one domain.
To be honest, I didn't even completely understand the purpose of UPS, the "advertisements" didn't seem accurate enough and I didn't care to read more about it back then because everything worked without it. We've never had UPS and we can see peoples' login names, real names, email addresses, etc. just fine inside SharePoint. What does UPS actually give us? The ability to sync even more properties from AD to SP and/or the ability to sync users and properties from SP to AD? Can't SP sync anything from SP to AD without UPS?
Anyway, to the real question. A new feature request came up: we need the ability to create new users without ADUC from the web (not necessarily but preferably SharePoint), while not affecting or endangering the current users in any way. What's the simplest route?
I think the nicest way is to install UPS. UPS is a pain to set up and configure, but it seems like it's the perfect tool for the job. Am I right? Can it be set up so that we delegate a new OU for this purpose, new users by SharePoint will be created in this OU, while current users will remain in another OU where they are now, SP will have no control over them, and they will still be able to login? Forms/claims auth and anything else is not needed for this way, right?
Do the new users have to be in an AD at all? Does SharePoint have the ability to create users in the content databases or something? Or should we poke around forms and claims authentication? What other ways are there? Or should we just leave SP as is, and create a simple, custom application for AD user registration and that's all?