I think there are probably places on HP where you can find more info than I have, and I'm newer than you in some respects. But I will try to give some ideas that I see.
One thing is that your writing is hard to understand in some areas. I believe that might be a language difference? I notice you are from Germany, how familiar are you with English? Don't get me wrong, if English is a second language to you, you are doing really well. But it can still make it hard to read sometimes.
Also, if you look at some hubs that are ranked highly, you will see that they break it up with sub-headings. Strange as it sounds, this makes it easier for the human eye to work through reading all of it.
That's my two cents. Hope it helps a little. =D