how did the romans treet the people they conquered? which other empires..............?

depends upon the civilization they conquered...i.e. Rome hated Carthage, and killed the majority of them. They did the same with the Gauls, the Julii hated the Gauls, and Julius Caesar was the leader of the Julii when they conquered Gaul. When they made it all the way to Egypt they were more interested in ruling the civlizations as subjects to Rome. Same with the spanish, the Germans, the Dacians, Thracians, Scythians, Pontics, Seleucids, etc.

For the most part the Romans allowed different cultures to exist as long as they worked with Roman authorities. If the natives were belligerent then the Romans would destroy and enslave them