Well, what do we know?
First, we know the beginning of this. Shakky just rolled up to Hachinosu and opened a bar, seemingly just to use the pirates there as a meat shield to protect her from getting arrested. Plus, she just seemed to have the idea of opening a bar before she even arrived on Hachinosu, because she had everything planned and ready to get built as soon as she got there. She even seems to have had a apron packed and everything. Unless the pirates made that for her, too, at the last minute.
Second, we can speculate a little of the middle. Shakky likely ends up getting kidnapped, and brought to God Valley. Why and how is still up in the air. Did a Celestial Dragon fall for her? Did the Marines kidnap her specifically to draw the Rocks Pirates out for a ambush? Did Shakky voluntarily go as part of her master plan? It's hard to say at the moment.
And we know the ending. Shakky ends up running a different branch of the Rip Off Bar on Sabaody, alongside Rayleigh.
There is one other thing to keep in mind. Back in Chapter 522, Granny Nyon said that both of the previous Queens had Love Sickness. This should include Shakky (unless there's ANOTHER Kuja Empress we don't know about, but I doubt it at this point). And some translations even say both died of Love Sickness. The official translation says that both previous Kuja Queens died, but some fan translations I've looked at are a little more ambiguous with their wording. So, it kind of depends on how that scene in Chapter 522 was actually supposed to be translated.
Another thing to keep in mind is: Shakky probably didn't PLAN on getting kidnapped and sent to God Valley. I mean...maybe she's some sort of 4D chessmaster. But, I don't think she could have seen that coming. Unless she has better Future Sight than anyone in this story this side of Joyboy. So, if Shakky actually does have a plan, it's probably only involving Hachinosu. Not God Valley.
Another question we have to ask is: How much of Shakky's plan is actually about Rayleigh? Was Shakky's plan all about finally getting Rayleigh to admit his feelings to her? Or did all this have nothing to do with Rayleigh?
So, now, onward to the actual ideas, finally.
Maybe it's possible Shakky was trying to fake her own death? Maybe Gloriosa/Nyon just went along with Shakky faking her death to help her "sister" out. That would keep the Marines from constantly trying to arrest her. And it might even keep old fans of hers from trying to track her down. The problem with this is...Shakky's not exactly trying to hide herself on Sabaody. Her name's on the bar and everything. And everyone seems to know Rayleigh's here too. So, if she was trying to fake her death...she was really lazy about it.
Another possibility is that Shakky was just honing her skills as a wife, more or less. She opened the bar, in order to practice cooking and cleaning a bit, so that she'd be ready to do it for Rayleigh later. She opened a bar, because she wanted to be a good wife. This is pretty unlikely. One...because she's getting all the pirates on Hachinosu to do everything for her. She's might not actually be doing any of the work in this bar by herself. Also, it doesn't really seem like it fits her personality.
Another possibility is that Shakky was just trying to get used to being around men for long periods of time. Shakky comes off as really cool and collected. But, it seems doubtful that she's actually spent any extended period of time around men. She comes across as "experienced" and in control, but it's possible that's all a facade that hides her naivety and nervousness. She's raised on a island of only women. The only time she's around men is when she's raiding other ships, which only lasts a few minutes at a time. Being on Hachinosu is going to be the most time she's spent around other men in her entire life at this point. Plus...maybe she's curious that if she spends some time around these men her "power" over them will wear off and they'll stop fawning all over her. Maybe this is all a experiment to see if she can find a man who will build up a tolerance to her presence and won't melt just looking at her. Maybe she's just curious if Rayleigh is really the only man who can hold a actual conversation with her without howling like a needy wolf.
It's also possible this is all a ploy to get Rayleigh to "rescue" her. "Oh no, I'm surrounded by all these rough men, I wish someone would come to my rescue". Maybe Shakky's trying to make him jealous or worried about her? Something to make him show that he actually likes her? Some girls like to get chased, after all. And, supposedly, she was supposed to have Love Sickness at some point. Even though, her "strain" of this disease might be different than everyone else's that we've seen. Maybe she doesn't want to chase after a man, but she might enjoy her man chasing after her, at least a little.
Or maybe she was trying to rescue Gloriosa. Maybe Shakky really is just worried about her old friend and former captain. And she's set all this up, in order to sneak Gloriosa out of Hachinosu. Shakky did seem pretty worried about Gloriosa when she had her Love Sickness attack. She does seem to care about her "sister".
Or maybe she's trying to find some "cure" for Love Sickness for the Amazons. Something permanent that she can bring back to Amazon Lily. Her people are constantly catching this strange disease. And maybe Shakky's curious if being around the men can maybe help her find some way to permanently "cure" it, without the Amazons constantly having to leave the island. Maybe she's trying to find a "vaccine" for Love Sickness. The problem with this is, Shakky doesn't seem like much of a doctor. So, I don't know if she'd think along these lines.
Or maybe she just likes having boy toys around? Look, it's flattering to have guys falling all over each other, trying to make you happy. Maybe she just thought it'd be fun to have a bunch of men she could order around for a while? Who could say they wouldn't be at least tempted to try something like that?
Or maybe she's after Hachniosu's gold. We know there were deposits of gold and treasure on the island, which is why they're able to get supplies now. Maybe Shakky was just planning on stealing it all for herself? That way she could "retire" with a nice little nest egg. Or maybe she really is just running her bar...but charging outrageous prices, in order to get all the island's gold without actually having to steal it. Keep in mind, everyone on this island is "rich". And after this, she ends up moving to Sabaody...where the Celestial Dragons set up their slave auction house. Shakky might just be following the money, and squeezing crooked people out of their ill-gotten gains. This might be her "smarter, not harder" way of fighting back against powerful people. Taking money they don't deserve. Like Robin Hood, only in a tiny apron.
It's also possible that she really did just want to run a bar. There actually is a slight theme of women running bars in this story, for some reason. Ida has her bar on Elbpah. Makino seems to run the bar in Foosha Village, Luffy's hometown. Zala/Miss Doublefinger is running a bar after leaving Baroque Works. Mozu and Kiwi are working as bartenders after Franky left to join the Strawhats. Ririka is running a bar with her daughter in Shells Town. This seems to be something of a repeated theme in the story. I'm not sure why, exactly. Maybe they all just enjoy the sense of community and camaraderie? Maybe it's because bars are supposed to be places of relative "peace" and happiness? Maybe it's a "cool" way to show a woman's caring and nurturing side? Maybe girls just like booze? I don't know. But, it's happening often enough, that it's probably some sort of theme Oda's trying to convey. I feel like this is probably the most likely option, even though I don't totally understand it.
So, there's actually a lot of possibilities. It's hard to say what she's up to. But, I do tend to agree that Shakky has some sort of plan. That plan might go sideways once she's kidnapped and sent to God Valley. But, it'll be interesting to see what more we find out about her.
