How to edit this file? What are all those oor:name= etc. Wish to change default font. Is this possible?
I can not tell you how to handle this file.
I think the right way is to change the font you use the best styles. You can change existing ones or create new ones. These can be reached via the sidebar (F11).
If you want to change it permanently, you should save your created document as a document template.
How to edit / create stylesheets and document templates is described in the documentation.
If you have specific questions, feel free to contact us here.