Hello,
1) Add the following code in Theme Options > Styling > Custom CSS
.header-wrapper header > .container .container-wrapper {
padding-top: 1.14em;
padding-bottom: 1.14em;
}
2) It’s transparent but background color for the whole site is white. If you enable Header overlaps the content option in Theme Options you’ll see that header is transparent.
3) Go to Theme Options > General > Breadcrumbs > change the color, bg image etc.
Product image appears in breadcrumbs because you did not choose the shop page (WooCommerce > Settings > Products > Display > Shop Page > choose the Shop page).
Regards