There's only 2 things wrong with the default setup, which are the hotkeys for Nanovision and on-use Killstreak Bonus - N and P respectively, way out of reach.
I have my Nanovision bound to Mouse Button 4 (Logitech G400) and Killstreak Bonus bound to X. Doesn't matter as long as they are somewhere near your fingers lol.
The rest should be fine with default settings.
In rare cases players who require crazy accuracy have their Fire and Jump bindings swapped around, so they use Space to fire and mouse to jump. It helps to keep aim extremely steady while firing (since the spacebar has no impact on keeping mouse movement smooth) - basically if you're a DSG/Gauss/Grendel fanatic. In BF3 I snipe like this since long distances require extremely steady aim.