Look at many of the world descriptions and you see references to ruins... actually this sounds like pretty fertile ground for the prospective Zeno-Archaeologist. So with that in mind if I might ask...
...do these ruins appear to all belong to the portal builders? Or is there evidence of other past civilizations in the Third Horizion?
...does it appear that these are ancient bygone races long extinct through the natural course of life... or is there evidence they had a little... "help" along the way?
...and is there any evidence of religious sites amid the ruins? Say for example something like pantheistic entreating to higher powers and certain dark forces between the stars...
...interesting to note that following a disease outbreak in Taoan a multi-faction strike force (including one with a recent schism against the Zenethians) comes in and blockades the portal in. Any rumors or evidence that the powers-that-be suspect this is more than an epidemic?
...is the arrival of the Xene Emissaries the first recorded contact with alien intelligence for humanity? Or has there been prior contact in the years before the Third Horizon?
Many more questions and thoughts to come though I'm dealing with my own overwhelming arrival of creatures from beyond (my two precocious neices from out of state:) but will chime in again soon. Till then!