redstorm - 2:47 pm on Jan 31, 2009 (gmt 0)

I'd like to answer you according to my practices:

A) Based on that person's comment, can we assume that the content translated to traditional is considered duplicate to the same content translated to simplified?

No. Search engine will index your webpages. The common consensus among Chinese webmasters is that simplifed Chinese tends to rank better in Baidu.

B) If I use robots.txt on one set of pages, doesn't it mean that that set of pages won't be indexed by any search engine?

Depends on. If the search engine follows Robots.txt Rule.