you really shouldn't be making too many pawn moves in the opening. i tend to make three or less pawn moves depending. any more and you could find yourself falling way behind in development.
i'll leave the open files rook question to someone more advanced.
pretty much every game i play flies right out of book immediately. or, if it is in book, then i'm not familiar with it because my study of multilple openings is tiny. but i have 2 questions today:
the first is--how do you decide when to stop moving pawns and work within the structure?
and the second is--everyone raves about the open file and getting a rook on it as quick as possibe and then 'using the open file to attack'... but man, whenever i try those files get all bogged up or i'm forced to swap rooks. how am i supposed to truely take good advantage of half-open and fully open files?