connection between Tserriednich and Kurapika. First things first, these are my insights.
1. Kurapika's mission aside being a guardian. He knows where the Eyes are. And he knows who generally holds them at this point of time. Only few eyes were auctioned in York Newcity. He will stay on his guard, and wait until he carefully analyzed all the Prince Nen Beast abilities. And that will be a longer state of time, until the Succession War is not over Kurapika will stay guarding.
2. Phantom Troupe once had a difficult mission, to kill all Kuruta Clan people to get their Eyes to be sold. And they retrieve it to once again sell it to a higher price to the one and only Tserriednich. This erase the idea that Tserriednich is the one who gave that mission to the Phantom Troupe. The Troupe might find Kurapika first, as we all know he killed Uvo. This is why the theory of Hisoka helping Kurapika again is fantastic.
3. Tserriednich holds a collection of rare body parts. First theory, in his character type. Do you think he will kill and defend his collections or it became not too important now as he is now drawn to know Nen. And to his character type he will just give these Eyes away, than to proceed in winning the succession war. He can just give it to Kurapika. Else if it's really Tserriednich who gave the mission to the Phantom Troupe, and the Troupe didn't sold everything to him. Kurapika might re-cast his chain of conditions.
4. Hisoka as we know him. He is fond of strong people, and in that Whale Ship, there are tons of Strong people. First, he can go anywhere. To the upper levels, or directly to the other Prince since he was being recruited. He don't mind being seen by the Troupe, because it will trigger the War.
5. All of you are focused on these characters. But the truth is that, these might just be playing in the hands of the Zodiacs. This might be the best Arc to highlight the difference of the Zodiac members among the Princes, Phantom Troupe, Hisoka and Kurapika. If the Phantom Troupe is really on the move they can just kill everyone on this ship like in the Auction House. Maiztrom Nana is on the move, and not stating any word of progress in his strategy. It was like being kept to surprise.