Can someone help? I have a 400 page InDesign document, which contains only text and vector graphics.
Please repost in the InDesign forum, as that is where you are creating your pdf file. Include in your post, the version of ID you are using. You will get much smaller pdfs if you don't need to include fonts in your pdf file, but you may be able to get a smaller overall size if you embed the entire font rather than using font subsets due to the size of your file. Obviously reducing the size of your video is paramount. Perhaps you should host the video on the net rather than embed the video in the pdf file.
If you wish to use Acrobat to reduce the size of the pdf, you can post in that forum for tips on how to reduce PDF files. In the later case let people know what version of Acrobat you are using since the tools are slightly different in different versions.