Re: Private blog entries
Yes, permissions for features (articles, galleries, images, ) are on a per object level, not on a per-item level. If you want different permissions, you need to use different galleries (one public, one private). In a wiki page, you can use the wiki plugin Group to display different contents based on user group (one for anonymous, one for registered, for instance)
There is no permissioning that will let you control items inside an feature (like blog entries)
gary