The only way to find out is to use it, then let it idle and see if the fan when it cuts in can bring the temps down so that it goes off again.
I don't know how much return flow there is on the rst, turbo return to tank, but as it's flowing should be ok, the water pump is working or it would just heat up within 5 minutes and boil on the spot.
From your reading of the gauge I wouldn't be worried, the gauges in fords are notoriously crap and inacurate anyway,
tabetha