1.2 - further and farther, the Qin Dynasty??

[Ludens]

I can't understand this line of reasoning... including China in a map with the rest of the west is no more unrealistic than including the Iberians in the same game map as the Bactrians. Sure, it would be unrealistic for the Chinese to march on the Seleucids, for instance, but then again, it's just as unrealistic for the Ptolemies to march on Carthage, or the Macedonians to invade Iberia. Besides, within the game numerous mechanisms could be put in place to prevent the Chinese spreading west too easily (the sheer distance, for one).

I am not sure what you mean. There was little military contact between the Chinese and Hellenic worlds, so I'd say it is realistic to place the map border between them, in so far any map-border can be realistic. Yes, it's unlikely that Bactria would wage war in Iberia, but apart from sheer distance there is no geographical barrier that makes conquest impossible, unlike those between China and Bactria/India.

That is, of course, not taking into account hardcoded limits to city, unit, culture and faction numbers.

So how come we dont have roman records that say things like "the seres live in funny pointy houses (pagodas) and their eyes look funny"? (i know that sounds bad to say but i really dont doubt the romans would've said that)

That depends on the Romans that went there having written it down, and preferably published it so there are multiple copies; and this writing to survive it to the present century. The former is not that likely, as these would have be working merchants, rather than gentlemen of leisure like most historians were; and the latter is next to impossible unless some medieval monk took the trouble of copying it. Basically, unless someone of considerable means and time went there and took the trouble of writing a long story about it, we would not have heard about it. And even if they did, chances that the text would survive to the present day are small.