1) Add a link to the cart button. set the type of the button element to button and in the property inspector, set the link to the cart page.
2) You can do the same with the continue shopping button to link it to a specific page
3 - 4) see the following tutorials:
5) What paypal system, are you using? Paypal standard? if so, find the following form element on the confirm page:
<input type="hidden" name="currency_code" id="currency_code" value="USD" />
and change it to:
<input type="hidden" name="currency_code" id="currency_code" value="GBP" />
6) You would change that in the eCart Add to cart server behavior
7) I would that would be referencing the items ID.