I've finished the game now, but still never found out how to conclude the following:
I never found Amra's grave (in a desert area, at the foot of ruins - Mulandir?)
I never found any Shadows and thus never used the Shadowring.
I never found out about the Trickster.
Just curious more than anything! Thanks....

********Should be obvious, but I'll note it anyhow... SPOILER ALERT********
You must be wearing the Shadow Ring to see the Shadows. You need to beat three sets in different areas, but I believe there are more than three areas where they can spawn.
Amra's grave is located in the Howling Mounds (west of the ruined city, near the lake). One set of Shadows will also spawn there, in the far west.
I can't remember the Trickster quest right off but there's a walkthrough for this game at IGN.

Thanks, Luned. Yeah, I don't think the Trickster quest is very important anyway, so no problem there!

amra's quest is one of the longest in the games.
It grants you a very nice armor :)
the trickster one however is not important