Ok, I'm planning that this will be a work in progress, but here goes nothing:
Sleep shouldn't be a problem. Humans are very adaptive, check out sailors for example. They also just completed a long space journey which should have put more of a strain on them. Also today's astronauts on the ISS have much shorter days. And if the worst happens, they can just build a house and close the windows and sleep as they need it.
As for food, I imagine that this would mess up most of today's already overbred plants, but I am not aware that anyone has studied this. Is them having genetically adapted crops or just indoor plantations an option?
If you have slaves however, this could create some tension. Fatigue and psychological stress could be interpreted as a result of the very planet's cycle. I think this would put even more of a strain on the slave-master relation, making your society a time bomb - especially since so few people exist. It should be easy to run away and live in the wild for a couple of them or even overthrow the structures. It should also depend on what the company expects of them. If the slaves have to keep a tight, inconsiderate and/or earth-like schedule without giving them the chance to adapt, this could lead to serious problems - check out long-term sleep deprivation. And if you have ever dealt with studied economists, you will know that they will not have planned and thought through fully in advance.