This is an interesting idea!  A couple pieces of feedback:

There are some typos in the blackpaper.  (I like the idea of black, though!) 

On Page 4, for example: In the case if double-spend attempts prevented by a mechanism there will no more problem existed.

I think it might worth investing in having an editor look through the document; perhaps for a bounty?

My other main question is about the value of the "instantaneous" transactions.  Retailers today are already waiting ~30 days to receive their money in Fiat from Mastercard/Visa.  My suspicion would be that 10 minutes is not too long for them.

Do you think that this "instant" value proposition is mostly for the p2p user?