1) It's interesting that you find the App Store description better, since the text are the same - on my product page, I just reorder them and put into different sections.
Cyberspace is a collection of tiny little features that add to the users' browsing experience, and indeed, I find it difficult to put them into words, trying to sell to the users.
2) I would love to hear about other social bookmarking services. I am only aware of Pinboard/Delicious and wish to add more to Cyberspace. Currently they're in the simple form of each site's mobile version, which I find suitable for a small screen/popover. In future version, I will add the ability to add your own service to Cyberspace.
3) That's a great idea.
I wonder if you want to give Cyberspace a spin. I'll send you a promo code right away.