Re: broken seal on windshield?
some focus' are equipped with a "cabin filter" (and yes, also the same as pollen filter, it's located under the cowel on the passenger side)
sometimes in the reqular maintenence we will (i'm a ford tech) check to see if said focus has a cabin filter, like i said, some do, some don't.
as for water leaks... i know on earlier models there has been problems with the moulding across the top of the windshield will seperate and cause leaks and windsnoise. but it's very possible that the seal has dried or cracked, or seperated.
but as already mentioned.. your best bet is to just go to an auto glass shop and have them check it out.