If it works, then you can safely change the other folders as well.
The only folders we create and set permissions on are the imagesupload, webassist, and Connections folders. We specifically set them to 777 in order to allow the editor and file uploads to work properly when editing.
However some ISPs have it set up in a way that allows 755 to work... it appears they may also disable 777 at that point for some folders. In your case updating all to 755 should be fine since it appears your web server is set up to work with that setting.