Hi Ascanius.

Like the others, apologies for not replying to your question, it's a shame to note that you stopped the progression for lack of replies. My choices, concerning your options:
C3, L1, R1

As for the second map, the one with states, here's some notes:

- Organized states would also spread around the coast of the western lake (north of region 20), I think, and it's closer to the origins of civilization. It's an area where climate is not so harsh because of the huge inner sea and where mineral resources must be abundant because of the mountains around them and the amount of rivers flowing (I'm thinking alluvial gold mainly).

- The roundish west coast south of those inner seas is hot and rainy throughout the year - more than the difficulty to get there (coastal navigation is always possible for roman times vessels), the nature of the land is uninteresting for expansion/colonization: dense rainforest, populated with semi-barbaric cultures, which might have land contact with civilized states (and, hence, not so backward military tactics and weapons).

- I second groovey on his comments about the Empire (nation #1) - maybe too large and too disperse. I am very curious about the placement of their capital and how it went from local power to huge global player.

Like I said before, this planet of yours and this area in particular is a great area to develop an "alternative history". The conditions alone spark my imagination and your excellent art just makes it that much more irresistible!