Confusing UI to add field-based feed display

In testing #2019091: Complete Configuration schemas for views row → I have run into a range of issues with the UI for adding a field-based feed display to a view. I'm opening this to get feedback, but I expect it to lead to us opening other issues for the specific problems raised.

My initial aim was purely to write the config used by Drupal\views\Plugin\views\row\RssFields. I started at http://localhost/drupal/admin/structure/views/view/user_admin_people and clicked +Add > Feed.

UX problem 1: If auto preview is enabled and I scroll below the fold I'll see messages saying:
- Display "Feed" uses a path but the path is undefined.
- Row style plugin requires specifying which views fields to use for RSS item.
Ideally this information should be prompted for immediately after I create the feed. At the very least the messages should be displayed at the top of the page and instruct the user about how they need to resolve the problem. The path option isn't too hard to spot if you're prepared to examine the page, but it's a bit of a leap to realise you need to click the Settings link for Format > Show > Fields to resolve the second error.

UX problem 2: Once I clean on settings, I am shown a list of 7 options, some of which are easy (e.g. Creator > Username makes sense), but others require more detailed instructions (link and guid particularly).

Now I know which fields the RSS field needs, let's set the ones I can and then go back to add fields for the rest.

UX problem 3: If I try and set just some of the fields I am told the other fields are required, so I have to click cancel and throw away the selections I have made. Once back on the main view edit form there's nothing to remind me which fields I needed to add.