congrats on the focus
i'm not a believer in any oil additive, if you use quality motor oil you shouldn't have anything to worry about.(motorcraft 5w-20 is a very good oil, priced very competitively)
now on to your question that almost everyone on here is going to disagree with me, first oc, i follow owners manual and i have never seen anything in any of my new cars about short mileage first oil change, what may have been the case 50?years ago is not the case now. over the last 25 years i have bought 9 new and 3 used fords and have followed whatever the owners manual reccomends for oc, first and everyone thereafter, either 5000 or 7500 mi. depending on model, some we have had in excess of 200,000 mi. and never any lube related problems. if manufacturers thought there was a need for an early first oc, trust me it would be boldly stated in owners manual. i am well aware of all of the parts wearing in together internally, but you have an oil filter, so again just follow owners manual
forgot, motorcraft filters are very good also