Can you put static folder in project root, rather than app root?
Django doesn't say any such thing. Put the static folder wherever you want, as long as you include it in STATICFILES_DIRS so that collectstatic will find it.
For example, if I want to use the same style.css for all my apps, where should I put the static folder? I'm pretty sure Django site says to put it in the application folder? But what if I have multiple apps?