It all depends, it's a matter of taste really. With DW, you will produce rage more quickly, and so you can spend it on abilities more often, but you WILL miss, a lot, because of the lack of +hit at lower levels.
IMO DW starts to shine in the higher levels, with all the +hit and all, and it is definetely a contender for top DPS in warrior terms (if not THE dps build for the warrior)
With Arms (or 2H fury) the damage will be more "constant" (as in lack of the massive miss streak of DW) but your rage generation will be more spiked.
I'd say try them both, and see what fits your playing style the most.
About your build, you should really focus on one tree while leveling, because spreading yourself like that, will only make you weaker in all aspects, and strong in none. Besided, it's better to reach your talented instant as soon as possible.
What do i recommend? 2H fury all the way to 40, and then you can make up your mind about switching to arms for MS or scale all the way to rampage.
I guess it's better if you wait for a more experienced opinion from some other warrior.