Hi Hanna Simpson. Thank you for the message. I tried to clean up the references you added. Just for reference, there's nothing wrong with citing non-English sources as long as they satisfy WP:RS, but if you do then it's sometimes helpful to provide a brief translation of the relevant section per WP:RSUE. This can be added to the citation template using the  parameter (See Template:Cite web#Quote). Translations do not have to be professional quality; They just have to be sufficient enough for the reader to understand how the cited source supports what is written in the article. 
Regarding COI, you are considered to have a conflict of interest because you have stated you are an employee of the museum at User talk:Materialscientist#Ottoneum. That doesn't mean you can never edit the article, but it does mean there are certain limitations placed the type of edits which are considered OK for you to make. COI editing is not expressly prohibited, but it can be a bit tricky to do so it is something which is highly discouraged. It might be a good idea for you to take a look at WP:PSCOI to see what these kinds of edits are. Of course, what you know about the museum is true, but what can be verified through independent reliable sources matters more to Wikipedia than what we may personally know about a particular subject. The information on the museum's official website is considered to be a primary source, so it's usage is rather limited. Wikipedia articles are not really supposed to reflect what a source says about itself or what those connected to the source say about it; Rather, articles are supposed to reflect what independent reliable sources say about something. So, any sources you can find which discuss the museum and are independent of it would be helpful.