No Stock Issue - Deleted Orders

Hi everyone.

I'm actually trying to set up the Hikashop component for an Art Gallery website. The component is fine and seems to be working, but I have encountered a few issues. The most important of them is how to get the items to refill their stock when an order is deleted. As I said, it's an art gallery website, so we sell unique products. When I delete an order of an item from the back end of joomla, I have to manually reload the available stock from 0 to 1 for the item to be available for sale. How can I fix this, so that, when an order is deleted the available stock comes back to 1 automatically ? I've already tried to play with the "cart retaining" function, but it does not solve anything.
The second issue comes hand to hand with the first one : How do configure the component so that the available stock decrease (from one to zero) only when the command has been PAID and not simply ordered. I don't want a piece of art to be unavailable because one customer wanted to buy it and finally changed his mind before the payment. How can I check within the component that the payment has effectively been made ? I cannot spend my time going back and forth between sites and email address, to check if orders have been completed. If I could solve those two problems I would have the perfect component

Thanks,