I have imported my sites from Google Reader when I started using NewsBlur.
Now, if I add a site directly to NewsBlur will it be synced with my Google reader account automatically?
Similarly, if I add a site to Google Reader, will NewsBlur fetch it from Google reader automatically?
No it won't NewsBlur will only access Google Reader when importing your feeds. If you add feeds to GReader, you will have to reimport, which deletes any sites you added to NewsBlur between imports.
See this thread with additional info by Samuel https://getsatisfaction.com/newsblur/...
I'll just ask this here: does anybody want a merge feed option for when you want to re-download your feeds from Google Reader? It would be a checkbox on import, but it would just merge as safety as possible.