Different browsers do show the maps in different ways. I had a problem yesterday which was cured by turning off shadow.
As to driving directions from a UK point of view they are not much good to me as there seems to be no way to have directions from a Motorway exit. I have however compromised and found a road or postcode close to where I want to start the directions from.
As to non display of directions check that the directions map id is the same I have had it not be when I've been experimenting.
Wish I could find an easy way of locating a position on a map and then extracting the location coordinates