Yeah, I'm not a fan of the cap retention thingy.... the cap hangs on the body work! I can't even remember what car it was, but I was impressed with the system than allows the cap to rest in a cup on the fuel filler cover.
With regard to buying Ford oil and BP fuel, do as you please but I'm filling up with whatever fuel is cheapest and topping up with Tesco value 10 40
. Seriously, don't skimp on oil but don't feel that ford oil is the only option.
Now.... best go and check my oil levels.... just covered the 2000miles mark the other day!