Abaddon said:2. The trick gifting techs around etc at the era change.. how do you do that? Or more specifically how do you do it for more than the entry techs (he seems to have managed to get more)
When learning the last tech in an era you use "what's the big picture" and acquire all techs from the AIs BEFORE you do anything else. Then you get your free tech as some second level tech.
With respect to getting cities bigger than size 12, in certain situation that MIGHT pay off. However, of course, you need Sanitation an optional tech to do this. Often enough it doesn't pay off to research Sanitation (though at higher levels it might, but NOT at Chieftain).
I don't know why he built roads. The value of specialists depends on how much corruption a city has. People have finished with better dates. See the Large Chieftain SS table.