Repeats in your performance Pieces:
You are not required to do any repeats in the examination..however no one is really stopping you doing them if you really want to! However , any Da Capo or Dal Segno indications MUST be observed..as these usually return to the beginning which changes the form or the whole piece moreso than a repeat of a section.
Even when not doing the repeats , its good to know how the signs work and what they mean as you could be asked about them in your General knowledge questions!
whilst some general pencil markings are not going to get you in trouble..be sure to get rid of anything that could be a clue in your general knowledge questions!
Page Turns in your Music:
It's a students responsibility to make sure their pieces can be played without altering anything to make time for a page turn...your performance should run smoothly without hesitations. You could solve any problems by photocopying extra pages or memorising any passages.
If you need to have a larger spread of Pages..consider a page turner , or bringing in an extra stand so that you can spread the pages out over two stands. Unfortunately , you cant be asking your examiner to help you out with page turns.
Having said that , whilst photocopies are generally not allowed during an examination , you can use them to assist with page turns , so long as you can show that you own the original music too!