BuddyPress.org

Actually thanks for the post. This is a something I have been doing (trying to do) since wpmu 1.0. I use WPMU / Buddypress with young (elementary school students 6-12 years old) so simplicity is a must. The New Blog Options plugin (if it works as it says it will) would make make perfect customization possible. Here are a list of WPMU plugins that I use or have used that might help. I am in the process of retrying everything to achieve exactly what you are trying to do. Let everyone on the forums know how your testing goes. Hope this isn’t too long. I added links to save time since there are sometimes plugins with similar names).

New Blog Options – this one is fairly new (still beta), and I haven’t tried it extensively yet, but it will allow you to clone on blog setup with it’s plugin options etc. to all new blogs.

https://wordpress.org/extend/plugins/default-blog-options/

Limit Blogs per User – if you don’t want them making more than one blog (set to 2, one is the main buddypress blog and 2 is their own blog)

https://wordpress.org/extend/plugins/limit-blogs-per-user/

WPMU New Blog Defaults – this will allow you to restrict menus, change default links, etc under the Options in the Site Admin menu

https://wordpress.org/extend/plugins/wpmu-new-blog-defaults/

Members – this one takes over where the old Role-manager plugin left off. Haven’t had time to check it out yet, but if you could use this with New Blog Options it would allow you to very finally tune what your users could do and see.

https://wordpress.org/extend/plugins/members/

Adminimize – again I haven’t played with this for a while, but if you could use it with New Blog Options, then you could simplify the look of the menus for your users too.

https://wordpress.org/extend/plugins/adminimize/

Default User Role – will set the user role when a new blog is created

https://wordpress.org/extend/plugins/wpmu-default-user-role/

Plugin Manager – does what it says, allows you to manage which plugins users can set, which ones are automatically turned on, and which regular users cannot see

http://wpmudev.org/project/wpmu-plugin-manager

download link is: http://wpmudev.org/download/946613807_mp-plugin-manager.php

Of course with young people you might want to consider a privacy plugin like:

More Privacy Options – this doesn’t work with the feed on Buddypress, but if you search the forums it can be made to work or you can use the following plugin for feed privacy (Buddypress privacy should be coming soon)

http://wpmudev.org/project/More-Privacy-Options/

download link is: http://wpmudev.org/download/999830698_ds_private_blog.php

BP MPO Activity Filter – This plugin, BP MPO Activity Filter, does just what the name suggests: it filters BuddyPress activity feeds. Used with More Privacy Options.

https://wordpress.org/extend/plugins/bp-mpo-activity-filter/