Donation features/ Suggested items

Ok, so I chose the most complicated first website to try out.

1.) 10% of sales goes towards a donation option - but I want my radio buttons to default on a choice, so the customer can't 'add to cart' unless something is selected.

I know theres something I'm overlooking...

2.) Also, is there a way that the shopping cart can show the exact amount thats being donated?

One more thing:
3.) Is there a way that the shopping cart can 'suggest items' to upsell?

the website is http://starssignatures.com/pink

Thanks for your help!

1. You can set one of the radio buttons to be selected by default in the attributes controller page. That way one will always be selected when added to cart. It's the radio button that says Default Attribute
   to be Marked Selected: and is in an orange background in the radio button strip.

2. I don't know about this. You will need to code it, I think. I think default zc doesn't show attribute values in the cart, but someone else might chime in to correct me. I think the simplest way would be to show each attribute's value in the cart next to it's name, but you could also code it to show the attribute totals in the cart subtotals which would mean creating/altering an order totals module.

3. http://www.zen-cart.com/index.php?main_page=product_contrib_info&products_id=283