Timo, I understand, that trying to keep options to a minimum, is a good idea. But on the other side, you force users to use your App in a different way! Maybe, most of your users like to have sorting of the timeline in a descending order. But what is with users like me, which like to have IT in ascending oder? I now have no way to return back :-(
I think the more options you have, the more flexibility (and more satisfied users) you will have! And if you don't like too much options, think about a switch "easy Mode" /"extended Mode" so that advanced users can modify the appearance to their belongings.
It's only an idea. I will continue using Diarium, but I would much appreciate to have same more options for customizaton.