If I'm going to be out of stock for a while, or have discontinued the product I'll 'disable' it in my shopping cart. This will remove it from the view my customers see, but I can still edit it and re-enable it when I get the product back in stock.
Yes i will remove the sold item coz it is useless for my customer. And if the item is sold off temporary and now is waiting for refill,then i will put available status