You can both use shield and dodge.
^^
Not really, the weight of a shield makes your dodging much less ineffective (even more if you keep it raised), and if you keep your shield looking at the enemy, you can only strife left/right, which is much slower than the crazy mouse movement.
You can do it on a smaller scale, to have the projectile hit a different part of the shield, but most of the time you will not be able to completely dodge it. After all, a shield is mostly there to stop them, and you should not need avoid projectiles if you have one.