Having run a low-key website for a couple of months now, I came to the conclusion that I had to restructure it in order to take it to the next level. Underlying was a self-built (php) back-end which took care mostly of presentation and not on content management. By using a WordPress back-end advanced functions for presentation and content management become available. In a couple of hours I was able to build a custom theme, which covers the functionality I need.
Having set the structure for my new website, the next task will be to add preceding content and fine-tune the theme to display correctly on all devices. New content can therefore be expected soon.