Radu??

He wanted Radu for BuFu, because consorting with women was against his religion.

Yeah: the Ottoman Empire employed an army of men known as the janissaries: which were actually Christian boys of conquered lands that were forced to convert to Islam and then trained as soldiers. Remember that the sultan's tribute always included young boys. I don't know about molestation, but it was almost certain that Radu was turned into a janissary: he was young and he could be manipulated easily.

In actual history, important, noble, or influential people from different cultures were always assimilated into the Ottoman empire to influence or understand the people of that culture. This practice was done in many great empires such as the Romans and the Egyptians. Consorting with women was not against the Sultan's religion contrary to popular belief. Doing anything with just any women was. That's why he had a Harem in which only select and very healthy women who were worthy of the sultan were kept in great luxury. There were women who actually wanted to joint he Harem for its luxury but not everyone met the standards. It was like how some cultures saw their ruler as a grand mind worthy of only the finest things. So just any women was not even a question. Homosexuality was practiced by many rulers of different cultures such as the Greeks, Romans, the French and the British. But which ruler actually practiced them is a limited knowledge. Any sexual relation with Radu by the Sultan though is highly unlikely and was probably suggested in the movie for a dramatic effect.

As for Janissaries, they were taken as children. Some of them were actually given by their families to have a better life from the people of other cultures within the empire. The Janissaries were brought up to be strictly loyal and fierce warriors. They were trained by the best of Turkish Ghazis (elite Turkish warriors). Many of them were but not limited to Christian children taken from the Balkans. Othman's son, Orhan started the Janissary army. Janissaries were trained to be completely loyal to their Sultan, so Orhan had a standing, reliable, and fierce military force. In time, even other muslim and Turkish kids started to join. Not everyone made it in the training so the people who failed were either returned to their families or used for other duties in the palace (More like a 10 to 5 job). The Janissaries can be literally compared to the German SS or other elite and loyal divisions of the armies of other cultures.

Janissaries enjoyed a high standard of living. They influenced the succession of the Sultanate, they had political power, and several Grand Viziers were Janissaries. The luxury and influence of the Janissaries were so high at certain point in history that some of them even attempted to take over the empire from the Sultan himself. At this time or around the same time of
Janissaries I believe, another division called Bashi-Bazouks were formed.

There are tons of information in the libraries and online history sites, but hopefully I did my best describing them in such a short space. I wish someone did a historically accurate movie of Vlad's story with a high movie budget such as Dracula had. Even Dracula didn't have any good battle scenes. All we saw was just shadows of soldiers from the Ottoman army fighting with and getting impaled by Vlad who looked like little midgets in the movie for some reason. But until that time it seems, we'll just wait and see.