Re: ‘Favourite’ content
Haha… No it’s doable, but to be honest there are so many links all over the page at any given point, that having the same little icon next to everyone of them to add it to your favorite would be pretty ugly looking.
I think if I was going to do it, I would have a link in the header, and maybe a “bp favorites” bookmark in your browser, a mini app, that you can visit to add the current page to your bp favorites, with the type of criteria you’ve mentioned.
I see how it’s possible, and I think I will need this type of functionality soon myself, so I hope to be involved in the production of this later on. 
