1. you ask if the quest is linked to the Crab hunting quest or if you have to hunt crabs in order to complete it? If it is the first thing, look at the silkroad site. If the second:
- take a Chinese friend with you, preferably 35+ lvl or a good euro party(must be a share party)
- go to the end of the Asia Minor shore (North) till you see some crabs called Hungry megalopa(with yellow thingies on their heads)
- kill them till they drop the harp( they have like 48365487 hp

)
2. werent't 2 & 4 in your post connected? I mean, click on the moss, it summons some crabs, you fight it and get the egg? Not very sure yet, have to do it first
3. Go to the South down below the Siah dock(or whatever it should be spelled). On the map you can see the place as a circle below the dock. Kill champs pirates(the higher lvl ones - Brignates or whatever they were), till they drop a blue thingy. Get it and right click on it. It sumons mobs with yellow things on their heads, you have to kill them and collect another blue thingy.
Must have a very good euro party(share) with you or a higher lvl Chinese friend