Hi, Seashore Media..
Does EE support pages that haven’t been made in the cms itself?
EE will allow you to create pseudo pages using the Pages module. Or are you wanting to know if they can use standard .html or .php files they made themselves?
Does EE support options for visually impaired persons?
No, there’s nothing built into EE to do this. How would you do it for a regular .html page?
Does EE automatically make a robot.txt that gives access to some files, but hides others?
No, you’d need to make one for your client.
Can EE automatically generate a sitemap?
No, but there are third party add-ons that can assist you with this task. You can always query on Devot-ee.com.
Can EE automatically send notifications to editors to let them know something has to be updated?
One method that works really well is to use MX Modify Control which will allow you to send mail for different notifications.
Can EE entries (“pages”) have data in different fields, e.g. an agenda with the date and description from different sources?
Absolutely. You use different custom channel field types depending on what fields you want to use.
Does EE offer the option of site statistics within the cms?
You can gather certain kinds of stats.
See: EEDocs:// Stats Module as well as EEDocs:// Entry Views Tracking
NOTE: You’re going to want to become acquainted with Devot-ee.com which is the place to go for third party add-ons.
Does this give you enough information to go back to your client with?