Which of the following phrases are correct:

> 1. Ich habe frei
> 2. Frei habe ich
> 3. Ich bin frei
> 4. Frei bin ich

The original meaning is « I'm free ».

 - What is the difference between them?
 - Are these expressions exchangeable?
 - In general, can I play freely with the order of the nouns in German sentence, unless the verb is located on right place (#2 in the sentence)?