Try repairing your Office installation and starting it without any 3rd-party apps (which is what safe mode achieves). If you have any 3rd-party apps installed and Word works better in safe mode than in normal mode, it's likely one of those 3rd-party apps is the problem - it might need to be uninstalled & reinstalled.

Document corruption can usually be resolved by:
1. Create a new document.
2. Insert a new paragraph break at the very end of the original document.
3. Copy everything except new paragraph break in the original document.
4. Paste the copied content into the new document.
4a. Do the same for any headers/footers that weren't carried across.
4b. Do the same for any macros & userforms in the old document.
5. Close the old document.
6. Save the new document over the old one.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]