Activity 1 I am happy to say that most of what came up were the professional things that I had hoped were contributing to my digital identity, such as work with professional groups and things I have written. However, another thing that came up, which I was aware of, since I get Google notices of things that come out containing my name, was a very crude statement from someone with the same name regarding their participation in a crime. This could be a real problem if, say, a potential employer attributed it to me.
Activity 2 I do think, to a certain extent, we are what we share, at least in a public sense. Of course, we do not control all that is shared about us, hence my monitoring of my name using Google. I have tried to be intentional about sharing and publishing positive and useful things, both professionally and personally, because your reputation really is valuable, especially when so many people can be aware of you without your knowledge or consent.
I also agree that such wide availability of ideas does stimulate the thinking of others and we are much smarter collectively than we are individually.