I agree with Olivesmummy, emotions are important for kids to learn to read. After all, they already know when you're happy and that's how they want to keep you. Sometimes I'll play up a hurt more than I'm really feeling it, just so that DS sees that emotion. 'Guilt' or empathy isn't bad to feel - it's what motivates us to be good to people! I can see how artificially generating guilt in a child can be problematic - you need to show them how others are going to act if he'd done the same thing to them. They're going to see it anyway when they're socialising more, so it's not a bad idea to practice reactions to it at home.
What I focus on more is when DS hurts someone else, then I'll 'tend to the injured' and SHOW him how to be in this situation. He's really picked it up - more the conventions than real contrition, contrition is a vague concept at this stage of the game and they WILL get it in a few years. Meanwhile, there are basic social conventions like acknowledging when you've impacted on someone negatively we have to do, as social animals. So, now, when I say 'ouchies' when DS clamps a little hard whilst BFing, he looks up at me and says 'Oh, sorry, Mummy'. It doesn't take long
Also, without focusing on people's belongings much at all, and just reacting positively, with love, compassion and reason in our home, he's mindful of other people's things now. Not always, and that's normal, but a lot of the time.
Kids don't do things to people to hurt their feelings at this age. In fact, they're usually mortified to find that a consequence of their actions has been to take the fun out of it for someone. Natural consequence = someone unhappy = desire to get back to status quo of contentedness.
That's just the way I see it