Say i am the Ottoman Empire, Should Slavery be outlawed in the Colonies-if so how would you enfore regulations on native populance that may not want to end this lucrative trade?
By the time that abolition of slavery became a global issue, the groups colonized by the Ottoman's had little reason to like the Empire or to resist rebelling. Abolishing slavery in territories that aren't favorably disposed to subjugate themselves anyway seems a risky choice--unless the issue of liberation is one that is on the Ottoman agenda also.
I have to agree that it would be extremely problematic to enforce an anti-slavery law if it was deeply unpopular with the colony where you were trying to enforce it. You clearly are going to find it difficult to enforce a law in a colony which might be geographically distant and also where your own control might be tenuous.
I think that from a practical standpoint, you should allow the colony to make the decision. Some may not have enough citizens and need the extra labor. You don't care about human rights, so why not allow slavery? It's allowed in the Empire!
It would be very difficult for you as the Ottoman Empire to enforce these regulations if you put them in place. It is not as if you have the resources to police your entire empire, trying to find and root out slavery. You also have to consider that your subjects do not necessarily like you. Is this issue important enough to risk making them rebel?