I did a screencast on your site. https://www.screenr.com/aaPN
I reloaded a few times, loads properly in my browser. Image does not disappear.
It’s a bit slower, but that has to do with the speed of your hosting server, not the theme.
You have disabled font-awesome fonts, therefore the icons on the content boxes are not visible in the screencast.
Your server is not super fast, therefore when you click the reload button rapidly, you will definitely see some items not appearing, because you stopped the browser and asked it to reload again, it’s always in the reloading stage and never gets to complete! I don’t think your visitor will keep reloading your site, so why do it?
You can upgrade your hosting plan to speed up your site, so that you will not see loading issues.
Sorry, I don’t understand the following issue, that you mention. Please kindly elaborate with screesnhot.
-box slider over images i cannot change top box (of two boxes) to red
For woocommerce sidebar, it’s in Theme Options-> Woocommerce ->Woocommerce Archive/Category Sidebar You can set that to none.