OK, so I spend the last two days communicating with the OpenHAB REST API in much more depth than I wanted to. But at last I can report success. For now I'm able to have a test client listening to ther rocker switch button, without dropping any events or losing the connection.
Next step is extending this test client into a small library being able to handle all sensor types and the sitemap / home page.
Using the Apache HttpCore library means that my code can run on Android too since its part of the platform.
The bug with OpenHAB sending each message three times still persists. May it gets better when I query the home page instead...
