Hello,
1) It’snot related to our theme. Go to WooCommerce settings and disable stock management if you don’t need it http://prntscr.com/q5ia7y
2) Why do you use custom to hide breadcrumbs https://gyazo.com/62f54919419fb6b14bc0ca08b48d0943 If you don’t want to show them then go to Theme Options > Breadcrumbs > Breadcrumbs Style > disable, if you just hide content using that custom CSS you’ll still have breadcrumbs padding.
3) Because there is no image that you used in your custom code http://prntscr.com/q5idv1
4) Use header builder to change the image width and number of columns that it takes https://gyazo.com/10ec4fb8c5135d4e5255877e1b9b08fe
5) Edit arrows and bullets navigation to change the color http://prntscr.com/q5ipgf Edit slide and button layer to change the button color for the revolution slider slide http://prntscr.com/q5iq4m
6) Edit bullets CSS http://prntscr.com/q5iko1
Regards