I should have said that when holding the space bar down you should then click and hold to move the board around. You should see the cursor change to a hand. Which version of macOS are you using? You can try resetting your preferences: https://scrivener.tenderapp.com/help/kb/macos-troubleshooting/res...
What location are you trying to backup to? It sounds as if you might not be able to change the location because of it switching back and forth but if you can try hitting Apple-D when it flicks to Scrivener that should change the location to the desktop. Does Backup Now work? And are the backups bein...
This can be an issue with very complex documents with lots of notes or images. You might want to think about splitting the document up into separate Scapple boards, with links between them.
It can also happen if you a custom background texture set.
It sounds as though at some point you've changed the default formatting so new documents have different settings to ones you made prior to the change. The easiest fix might be to go into a document. Select some text and then got Format>Paragraph>Tabs and Indents and then set the first line indent to...
You may want to try compiling to another format, but one that is still readable by OpenOffice, such as RTF or DOCX. It might just be a problem with the converter.