Is there a way to see the questions where particular users (I choose) participate?
(I guess this should be in meta, but I don't know how to post it there)
You can either visit your profile or go to search and type in user:me
The results will look like this.
user:117153
to search for posts user 117153 participated in (since that's you, auser:me
would work too for you). $\endgroup$