Have you figured the problem out yet?
I'm having similar issues in Indesign CC. When I open a file I created a month ago, just spinning wheel for 20 seconds then I try to make another change and spinning wheel again. I can't do any work.
I ended up creating a new document to eliminate the issue with the inability to change the font characteristics. I think that was created from something that came in from the Word document. I copied all the text from the problematic section into text edit, removing any formatting before pasting it into InDesign. I'm still getting the spinning wheel often but I've been too busy to spend much time troubleshooting. It seems to happen more when I have large photoshop files open.
Do you have hyperlinks or cross-file cross-references? That can slow ID to a crawl if the destination isn't also open.