If I wanted the low-tech option, I'd create a User report with a filter for 'Entry Date in last 24 hours" and have it email to me every day. Some days it would be blank, but that's the lowest time-cost option for that part.
As for assigning default layout templates/companies etc, the answer is "Yes, but that may not work the way you expect." Within the SSO panel in Setup, you can go into the 'Map User Attributes' window and set default values for quite a few of the options on a User record, including those two.
Take care though, those settings do apply when the account is first created, AND every single subsequent login via SSO. It keeps reapplying them every time. If there is some attribute being sent to you in your SSO config that you can use to accurately determine the right answer every time though, that could be a way to go.