I've completed the uninstall and reinstall steps as indicated in steps 1-5.
I'm using the OneDrive for Business Mac sync client Preview and downloaded from the link you provided above.
Microsoft Office 2011, One Note and OneDrive for Business are the installed Microsoft Applications.
I clicked the Use Rich Formatting but don't see the Insert Image Icon. I have 2 screen prints to attached. Since the reinstall the CPU is running at 92% again.
Thanks,
Robert