Today, I started using the Twenty Seventeen Word Press theme.
Previously I was using the Shoreditch theme.
After looking at another blog using the current theme, I noticed that this new theme could be set up to do most of what I wanted.
For a comparison of my previous two themes see:
The current theme means that the annoying change of font size does not occur any more.
As you will see, the menu stays at the top of the page even when scrolling down.
Sadly, I have still not been able to show an excerpt of my recent posts in the sidebar.
The new theme may be slightly slower to load initially than my previous theme.
The menu is in a better position in the new theme.
At the time of writing, I could not see how to get the number of likes etc for a post to appear in the blog roll.
Update: I have sorted out everything (except ReBlog on the blog roll) using Sharing, Sharing buttons.