Hmm, what do you think about Sanji possibly being a little bit afraid of the dark? Like a small trauma from being forced into a dark cage. Do you think it is possible?
Your question make me think much about it so that I answer it quite slow. Take a closer re-reading the chapter 833 and then the whole Baratie Arc, I now don’t actually know which flashback is more traumatic for Sanji, those flashback would haunt him with ‘darkness’.
He lived 8 years with the Vinsmoke family, till now we don’t know how many times, how much long they put him in dark cage (and for which reason also still not clear) This must be waited to know, but for a child at that young age, just one time could haunt them forever.
One year later, the event of Orbit Cruiser happened, storm, meeting Zeff, shipwreck, and nearly starving to death alone in a stone cliff. The fact that, Sanji at that time was 9 years old child, and he spent 70 days alone (following Manga Original) before came to Zeff’s side and they spent more 15 days. In that amount of time 70 days, I’m sure that he spent through enough of storm, and darkness of the night, without food.
And till now I more and more wonder, where did that power came from, power to survive, for a kid like him, just one previous year, with Vinsmoke family he must be abused a lot. Normal kids might got mental break down, or if they don’t, they can’t have enough of power to survive like that, they would be haunted by the past and very weak inside. But in Baratie Arc, we all can see, it was the power of dream, his dream about All Blue, he wanted to survive by all cost because he knew that he could not die before finding out that ocean. That dream gave him power, to cope over the dark past of Vinsmoke family and survive in that stone cliff too. Now the root of that All Blue Dream becomes the key of this story. Where/whose‘s that dream/story about a sea from, it’s not confirmed to come from a book yet!! To Sanji, it gave him that much effort to live.
So, if the question is, may Sanji now still be haunted by darkness or not, I would say no, he may not. It definitely hurts him inside, when he remembers about the past with the Vinsmoke family but he is not haunted by that, anymore. He has grown up, strong in both vital and mental, if he could cope those 70 days on that stone cliff, he must already cope the darkness haunting.
And don’t forget from 9 to 19 he lived with Zeff and the Baraties. Zeff is strict but he sure loves his little eggplant and those 10 years Sanji must got enough of affection from people around him to step out of any haunt. I would say thanks to Zeff and all the people at Baratie a lot.