Hi Loftur,
The reason you are seeing so many words in English (and incorrect translations) is because the translation is really outdated. All of our plugins are translated by volunteers, and no one has worked on this one in a while. Would you be interested in updating the translation? That would fix your site and we’d give you a free license in exchange.
If you are interested, check out the Getting Started post where you’ll find the instructions and files you need. Make sure to follow step #6 so that all the new strings show up. If you are not able to translate it, you’ll unfortunately need to wait for someone else to update the files.
Best,
Leah