>>216031837
The ones that returned were a small minority. After almost dying crossing the ocean and from diseases, fighting hard, founding a town and then trying to defend the social position they attained, there was little reason to return. If they made it big they might bring their families, if not they might try to form a new family. You're right that actual marriages were not that common if they didn't have political reasons for it, but a lot of extramarital sex happened regardless.
>>216032207
There's a distinction to make between the first decades when slavery was still legal, the period when the encomienda system was still in place and the period after the demographic collapse, though. Sex slaves were definitely a thing in the early periods and in the later periods servants that were expected to fuck their masters were commonplace.
>Why then many governors were sentenced to dead because they enslaved indians?
Because the law was an useful resource to get rid of political enemies.