@presstigers I managed to get a little closer to what I want by putting this code in style.css:
.fbc-wrap{ text-align:center; padding:0 27%; }
.fbc-items{ margin:0px auto; }
The value of 27% was found by experimenting, I expected 50% to be perfect but somehow the breadcrumbs are horizontally crushed and put underneath eachother rather than side by side with that value. Stuff looks a little better now but the left side of the breadcrumbs are only well aligned with the menu on a 2560px horizontal resolution now, and the breadcrumbs are nicely centered on small screens (tablet, phone). On anything else it looks a bit weird now. I can’t get my head around it. Help would still be appreciated!