they'll only end them if other people report it, ebay personal themselves don't go checking stuff, coz they don't have the time 4 it, they only act upon reports. if your buyers are satisfied, you have nothing to worry about, if a buyer thinks that your shippingcosts are too high & reports it too ebay then they can check & if they agree then they would end your listing.
if your honest you have basically nothing to worry about
2 times actuall shippingcosts is fair, shipping insurance 2 times actuall is fair, 2 times taxes is fair, when your a powerseller then your making enough profit like that.
put in your description clearly how your shipping & other costs are build up, most people would understand that, don't understand why some people have trouble with this? the main reason why ebay said that they would end listings that have to high shippingcosts was to increase international sales, upon the many reports they have recieved from international buyers that the seller was charging to high shippingfees for them...