The air coming through the door seals is pretty normal I think on the expi and ford trucks around this age. I read somewhere that ford had been putting wrong door seals in these vehicles. I'm pretty sure there is a service bulletin on this. My doors even rattle because of the seals not being thick enough. I haven't bought new seals yet from ford because they are prob still selling the original ones that they put in there and they will only last so long again. There is a you tube video stating how this is a big problem with fords and they show how to run rubber tubing through the inside of the seals, that way they have more thickness to them, therefor not letting air through the door seals and less door rattling.