Highlighted but useless?? people.

[inteligint]

In Heroes Guild, there's a guy that is giving tours, he's highlighted green, is there anything special I can do with him?
In Bowerstone South, one of the little kids is also highlighted green, but he won't even talk to me.
Do either of these people do anything?

[swcarter]

I don't remember the kid, but the tour guide doesn't do anything more than give the tour.

SWC

[Greg.]

Doesn't the kid give you the sick brother one?

[Fire Monkey]

It's the little girl that introduces you to the Sick Child quest.

Have you collected a hero doll yet? If not, win a doll at one of the pub games and see if the boy talks to you about the school teacher's penchant for collecting dolls; this will start you on the Doll Collection quest.

[Loredweller]

Oh, no, he means the guide leading the outside tourists into the guild (there are usually 4 of them).
It seems to be one of relicts if abandoned questlines, there are few - though on my memory this one alone is green.