All ghost blogs have /page/x/ and /tag/foo/page/x and so on if there are enough posts to fill more than one page (default Casper pagination is 25 posts per page but it’s theme-dependent). Eg:
These pages are linked via meta tags and the sitemap but only if they exist. Without providing your site URL it’s difficult to see what the problem is but you need to check for anything that might be preventing those URLs from loading.
There are also no links to further pages in the HTML or the sitemap from what I can see so it looks like Ghost is doing everything correctly. Not sure what to suggest here, it seems like it’s just Google’s crawler trying to load pages that it’s guessing might be there
I was able to find a bug in Casper that generates extra URLs, although they’re usually in the form /page/2/page/2/. I’m not sure if this is causing what you are seeing, but I’ve raised it here:
I recommend watching that issue so that you can apply the same fix to your blog.
Personally, I just copy my edits into a new Casper copy every few versions. However, if you have made major changes to the theme this might not be a feasible option.
If you’ve made changes to a theme then you’re then responsible for keeping it up to date. If you’ve forked it with git and the changes are minor then you can probably merge upstream changes in without too much trouble.