Peadant Hunt quest

You could just complete it, you get 500 gold for each pendant so it can be quite profitable.

I think even when you complete it the journal for that quest doesn't go away.

You have to collect every pendant, which is tedious. Or else, it just sticks around in your Inv forever.

You can remove the quest by typing on the console
player.setstage DLC2RRFavor05 250

On the 360 this quest never completes. I just went back to all the now empty strongboxes to be sure I'd found and turned in every pendant. This is my 3rd run through the game with Dragonborn and each time has resulted in the same messed up quest. 

Yeah the quest will never end even after turning in all thirty three pendants (unless you kill Fethis to fail it) and to get one pendant you require a key not in the game so its a real mess and can't be finished on a console. On PC a console command can end it and the quest should be fixed by the Unofficial Dragonborn Patch.

^That fails the quest, but since it is a miscellaneous quest you wont see it as being failed.

I did this instead: found atleast one east empire pendant, took it back to Fethis Alor, and got the reward for doing so.

Now key in this console command "SetObjectiveCompleted DLC2RRFavor05 10 0"

Some strong boxes seem to respawn their pendants. This can also make the quest impossible to complete. When it comes to the elder scrolls games, I have just gotten used to stray incomplete-able quests every now and then and ignore them in my journal.

i tend to avoid giving the pendents or trying to find them

did the quest just say that even when you complete the quest it will never go away?