W/Salam

1. Yes, outline should be in form of phrases and should contain points which one would discuss in body.

2. Outline is essential as it facilitates the examiner and provides an overview of essay.

3. There should be no headings in body of essay; however, you can connect main headings of outline through transitory paragraphs.

4. Yes, one should not deviate from outline provided at start of essay.

Hope it would answer your queries.