If you want the nation to have dutch sounding names then change the national language to Dutch, simple! For graphics, go to the folder containing the flags (can't remember it off the top of my head
coz I'm at work but I know it exists) then replace the one already saved.
The main downside of your nation is that becuase they have no history FM see's them as the equivilant as say Faroe Islands (i.e crapola) and you will end up seeing scores like 8-nil against them. The only way around this is to either be the national manager yourself, or watch the games.
Best of luck mate.