Ok, yes, something unexplained and unaccounted for in the plot exists given what we know about it. The key here is that there are a number of easily conceivable and acceptable explanations for that plot hole. You don't have to dig deep, stretch far, etc. to come up with something to fill the hole. This basically means that is not terrible writing. The things we use to fill the hole are fan-fiction? Ok, so what? These fanfics arose from someone pointing out the plot hole, which we then filled with reasonable explanations.

As far as the fortune is concerned and him being able to hand it over, just think about what would happen if Kurapica got to use the judgement chain on Hisoka, and Hisoka was a real, loyal spider. There are any number of reasons Kurapica might want to keep Hisoka alive, one of which is to continue gaining information from him. However, he doesn't want his identity revealed in case their relationship is discovered by the spiders. So Kurapica places a restriction on him: "Don't allow any information you have discovered about me at this meeting, or will discover about me in future meetings to become known by the spiders." At which point, Hisoka would object, saying that should he be discovered, he's dead anyway if he can't say anything, there's no way he's beating all those monsters. So Kurapica modifies the restriction: "they are allowed to know that there is a restriction upon you preventing you from divulging the information they seek."

This would allow him to hand over the version of the fortune he handed over, answer chrollo in the manner he answered, and yet not allow him to let Pakunoda read his mind. Is this fan-fiction? Sure. Is it unreasonable? I don't think so, at least. And there are probably a number of other explanations the author could easily have fit in there if he was so inclined. It's not necessary though. The deception Hisoka weaved was solid enough to withstand the situation it was designed to.