Would it be possible to and/or acceptable practice to use a Content Template to format the results of a View? I have several views that need to output lists of posts, and it would be nice to only have to update one template instead of all the separate views.
I did try creating a content template but when I tried to add a featured image, I realized it was only giving me Pages as available sources of data, not Posts. I did not select any post types to use with the content template, since I do not want this to be the standard template that's used for single pages.
You can do this, but the dynamic source options offered in the editor are based on what post is used for the preview (which you can change at the top of the page).
If you are previewing the template with a page, pages don't have featured images, and hence featured image would not be available.
Choose a post for the preview that includes the fields you will want to choose as dynamic sources in the template.
If you are still having problems, you may find that you need to temporarily assign the template to the post types used by the Views purely while editing the template, and then you can remove the assignment before saving the template.