This seems very interesting. Political intrigue as a pit fighting abomination sounds like a fun thing to rp. 

few questions
Is it mainly Bio engineering or would there be cybernetics as well?
How inhuman could a characters be?
do fighters end up following wealthy individuals around as decorative conversation pieces/bodyguards?
is there some kind of collective dorm/barracks or are they housed in their masters homes/labs?
you talked about autocratic houses but who is in-charge of the civ as a whole, is it some kind of emperor or something more like a senate of the heads of the houses?