A rough guide:
So my eie sounds approximately like may AY-uh.
If you are learning pronunciation, it is a good idea to listen to native audio, because English spelling can only give an approximation.
Not always. Dit can mean it, but depending on context it can also point to something like this.
For example, if someone is holding up a book and says Dit is my eie boek, the idea may feel like This is my own book in English.
So the exact English choice depends on context, even though the Afrikaans sentence stays the same.