It seems like when you build a city you get whatever resources are produced by the tile in which it is built and none of the other tiles are worked (unlike say in civilization series).  Is that correct?

So, all other resources for the city come from special tiles or buildings, is that correct?

This implies than that expansion of the city is valuable only for:

1 - Strategic ownership reasons (i.e. an expanded border to keep monsters at bay)

2 - To acquire special tiles.

Is that correct?

Thanks very much in advance for answering what must seem like a simple question.  Maybe this is something to add to the tutorial because it is very different than other civ-like games... I spent several minutes trying to figure out how to change which tiles were be worked.