Question 1: Can we see and analyze the Goals and Funnels from origin mensurables in the Rollup?
Question 2: A visitors visiting all web pages available to the Rollup is identified as 1 visitor or as a different visitor in any measurable?
At Roll-Up Reporting FAQ - Analytics Platform - Matomo not so much answers to this topic:
Can I create Goals or Funnels or Custom dimensions for a Roll-Up measurable?
This is currently not possible. The Roll-Up measurable will show you aggregated conversions and conversions rate across all websites that you have selected. However, it is not yet possible to create Goals, Funnels, or Custom Dimensions for a Roll-Up measurable