Thanks for the comment. What exactly do you mean about incomplete information through hashing? Saito comes with a lot of backend cryptographic tools so it should be possible to do almost anything. One current feature that uses hashing is when players pick cards simultaneously -- they share their picks in hashed format before revealing the secret that prove their picks were made independently of the other player's -- not sure if this is the sort of thing you mean or you are thinking of something different.
The underlying game engine handles data transfers, abstracts away the complicated cryptographic data exchanges and makes sure that the game "stack" is the same. Once a new move is broadcast all of the players/observers add the received move to their local stack and then execute the instructions step by step until more input is required, at which point the game halts while everyone waits for the active player to provide input by "playing their turn".
In terms of game features, right now the core engine focuses on things like provably fair deck shuffling and card dealing and random number generation. Other features we hope to add which should benefit from the blockchain layer include things like decentralized leaderboards (everyone can see who won / lost public games so we can have distributed rankings), the ability for players to stake other cryptocurrencies on games (if people want they can even pay for games move-by-move), and the fact that game modules will be genuinely decentralized, which avoids the problems with distribution channels like Steam and/or the App Store, etc.
XMPP integration is a really interesting idea. What exactly did you have in mind with it?