From what I know the Social Theme is the only theme which was intentionally designed to show some content on the landing page in advance. Thus, why do you want to use exactly that theme if privacy is so important to you?

hi update, was still testing. And its clear what my tester means . It seems when i use the Social(premium) theme the site is not private anymore.
Is there an way to fix this?

@michael, your right.
its just as with others socials, dont share what you dont want to share

Okay, so let me refine my question:
What's the idea behind adding content to a community that you don't want anyone to see?

its not the community chat, its the user profile section .
Friends can see everyting there, Photo's(albums), Blogs, Video etc.

Its not the general wall post.

Maybe you can explain why you want to post something in a community that you don't want anyone to see?

good to know, dont wont to show, dont post it
shall add this to my disclaimer

I am afraid hiding from specific friend is not possible. Unless you block that user.