Without the inclusion of mining and the incentives to establish a mining infrastructure, how do you intend to provide safe decentralized verification of transactions?
The system currently uses the same consensus algorithm as Ripple. However, one thing David Mazières is currently spearheading is development of a provably-correct version of consensus.
(I think it's very important that whatever primitives you're building on have solid theoretical foundations, and I'm pretty excited to see the infrastructure improvements Stellar is going to introduce there.)
Which isn't all that decentralized. The only nodes that participate in the consensus are a handful of "trusted" nodes run by - well, in this case I don't think we know yet, but the Stellar foundation gets to pick who can run them. Those nodes get to decide which transactions are accepted, what fees are charged, the money creation policies, etc.
