Hi timethief, here are some answers for you.
The short answer is that most of what you've listed does not count as a pageview.
There are two different ways to get to a full post view from the Reader, and they both count as a pageview for the blog:
1) Clicking the title of the post takes you to a full-post view in the Reader.
2) Clicking on "X more words" on a Reader post takes you to the post on the blog itself.
We define 'pageview' pretty strictly:
- A full post view in the Reader.
- A view of any page/post/index-page/tag-page/homepage on a blog/site.
So while all of the things you mention indicate a user's interaction or interest in a post, they count as a pageview only if they result in a pageview as defined above.
Is a remotely clicked share considered to be a page view stat?
If someone clicks on a link shared on Facebook and that leads to viewing a post on a blog, that is a pageview.
How about a remotely clicked reblog? Is it considered to be a page view stat?
Same. If they click through to the source blog of the reblog, then it's a pageview. If they only view the reblog and don't click, then at this time it's currently not counted as a pageview on the source site.
When readers read only an excerpt of a blog post in the Reader and do not click into the blog it’s published on, which off site activity (see above) that they undertake constitutes creating a page view stat?
Counts of comments, likes, follows (regardless of whether they take place on the blog or in the Reader) are all available to the blogger, but they aren't pageviews, so they aren't counted as pageviews. A view of an excerpt also isn't counted as a pageview by our strict definition, but we might count them as Reader views in the future.