As has been stated, tools are mainly used to help you better focus on your magical workings. Therefore, you don't need to use a staff or a wand unless you feel you need one. I would suggest using a wand, if you do decide you need one, simply because it's small and wouldn't be as bulky and difficult to maneuver as a staff would be.
Perhaps this should be in Magical Items.
As mentioned, wands or staves are not required. You don't have to use one unless you feel you need to. They are just basic tools mainly used for directing energy, among other things.
Not necessarily, but having one is pretty cool. You can make it your own by adding gems, stones, runes, engravings and many other things to it. But to cast a spell, you don't need one but it can help. You can use your finger to focus your energy.
Oh and no, unless You preform only ceremonial magick, which requires all four basic tool's ( according to Aggripa, Eliphas Levi, Solomon ) but using wand makes elemental energy manipulation so much easire and precise. In apotropaism wand is highly appreciated in certain forms of exorcism, banishment and undoin g magick, though special wands are made for such purposes ( special wood, decorated in particular way, with certain gems and feathers , according to Eliphas Levi and E.A.Wallas Budge, among others ) and I would assume same goes for stave