Explanation
Box 1: Yes
With embedded canvas apps, makers can bring the power of canvas apps to their model-driven forms. Using embedded canvas apps, it is possible to create rich visual areas on a form and display data from a variety of sources right next to data from Microsoft Dataverse.
Box 2: No
Box 3: Yes
Reference:
https://docs.microsoft.com/en-us/powerapps/maker/model-driven-apps/embed-canvas-app-in-form