Crocodile falling for a Lucky that works at his casino really would be a catch 22 because on one hand- if he pursues a relationship and has her move in with him and stop working there so as to keep her close and avoid a scandal of dating an employee, people will riot at her absence and the buisness will suffer. (she got sick one day she was schelduled to work and had to call off and people were... very upset. he knows first hand how her leaving for good will go)
On the other hand, if she keeps working at the casino- I feel like eventually he will get upset and frustrated by all the attention shes getting from admirers and it will get harder and harder to hold back his irritation. Watching her buddy up to patrons to get them to spend... watching people come in just to shower her with gifts, spending their earnings right there in the casino to buy her drinks or jewelry has gotta be beyond annoying to him after a while. He high key wants to tell her to throw those things away, company policy- he will compensate her by buying her nicer gifts anyways.
Some patrons get especially pushy with Lucky and Crocodile has to fight not to kill em and destroy his reputation.
I can only see it ending one of 3 ways:
1) Crocodile snaps because of one of the above and finally says fuck it and pursues said relationship. (to what effectiveness? who knows)
2) Crocodile runs out of time to make a choice when he is arrested and sent to Impel Down and is left in HEAVY regret. (regret he intends to correct when he gets out. wether lucky will be receptive or not now that she knows the truth)
or 3) a clueless Lucky finally finds out just how rough it is here in alabasta for the common people, and feels enough guilt to try and leave her cushy life. Like wow, shes making so much money, she can have hot baths every night, and she finds out theres a water shortage in most of the country?! oh jeeze, she had no idea, she doesnt think she can keep doing this... maybe she can move someplace she can help, or donate her earnings to help, or- mr crocodile why are locking the door shes trying to respectfully resign what-
(bonus option if she tries to leave because she finds out the state of the country AND crocodiles role in it, which makes her trying to leave more angry and betrayed and less "thanks for everything, but im seeking a more humanatarian career now! I want to help people like how you helped me- oh shit he wont let me leave uh oh")
The rules in the casino start changing shortly after Lucky's arrival. Before this, it was understood that a certain level of touchiness from patrons was to be tolerated. Management would tell employees to just grin and bear it so long as it doesn't get violent. But after Lucky starts working there and gets touched a few too many times, there is suddenly a zero tolerance policy toward any kind of physical touch.
Gifts are now no longer accepted and have to be turned in if the customer insists upon it. The official reasoning is a vague "safety concerns".
It wasn't uncommon to see Sir Crocodile in passing around the casino, but that was all it used to be. You'd get a glimpse of him here and there as he goes about business, but now sightings of him are a daily occurrence. And he tends to linger, too. In the past, he never got involved with disputes inside the casino. At most, he'd point security to where the commotion was if they hadn't noticed yet. Now? If anyone oversteps with Lucky, he's storming up to them and escorting them out himself. Those people always end up with "lifetime bans", which is just code for: Crocodile murdered them and now needs to explain why they abruptly stopped coming in.
One of the things that helps keep the canon timeline of Lucky Break lighthearted is the fact that Lucky is constantly on the move. By the time she's heading to the next island, the locals haven't started showing extreme behaviors yet, so she remains largely oblivious to just how many people are affected by her.
But in these other timelines where she's stationary... problems begin to arise quickly. At first, everyone is just really friendly to her. Lucky's coworkers and regulars are always so happy to see her. Then they start wanting to do stuff together outside of work... and then they're showing up at her home. She doesn't recall telling these people where she lived. That's bad enough, but it gets even worse when someone breaks in just to try and get to her.
Not being able to move along to new locations constantly would highlight the very real dangers of having people obsessed with you. Lucky is perpetually acquiring new stalkers, leading to Crocodile moving her into a gated community and hiring personal security just so she can sleep in peace... only for her to show up in the middle of the night at his home because the security became obsessed with her too.
At this point, even Crocodile is struggling to understand what is going on. He knows this isn't normal, but he's already ruled out a devil fruit since he's overheard Lucky making plans with coworkers to go swimming. So what's left? What could possibly be doing this? She may not have a devil fruit, but did someone else who does place a fucking curse on her? (yes, actually)
Lucky officially moves in with Crocodile because he genuinely is out of ideas for how to keep her safe outside of that. He considered using Baroque Works agents, but quickly thought better of it. Trained assassins obsessing over her could turn deadly very quick. (but tbh the concept of Lucky having Bon Clay as an assigned body guard disguised as a new friend is really good)
Certain personality types can handle the amulets effects better than others. Someone more guarded and calculating can cope with the onslaught of emotions better than most, and keep it hidden. Lucky has no idea that Crocodile is as obsessed with her as everyone else. She also doesn't see it in Robin. Both of them come off as entirely normal, so she's downright eager to live in Crocodile's home.
She's finally starting to relax, meanwhile Crocodile feels like he's going insane from the close proximity. He wants to confess to her every second of every day, but he knows that she'll start to fear him as well if he shows his hand like that. So now he's debating if he should keep is mouth shut, or if he should just trap her here now and worry about regaining trust later.
Crocodile being so consumed by this makes it easy for Robin to start initiating her exit plan. She begins dropping hints to Lucky about who Crocodile really is. Leaving documents where she could see them, speaking too loud about plans when she's within earshot, outright making observations about how Crocodile appears to be a little too focused on her.
Eventually, everything blows up in his face when the Straw Hats show up. He gets arrested and thrown in prison while Robin runs off to join the very people who took him down with his Lucky in tow. He feels like a fool for not doing more to make her his before this, and he fully intends to rectify that as soon as he escapes.
