I cant find the answer to this, do you use the dodge the same timing you would use parry? Or is a successful dodge different timing than the parry? And does forward, back left or right matter or are you invincible for any of the four choices?
The timing is stricter and slightly different due to when the invincibility frames kick in. If you know how to parry correctly, the timing is most similar to that, but it's also dependent how close you are to the attack in question because certain attacks can still catch you based on the boss fight in the demo (for example, using the sidestep on the chainsaw grapple pounce will still get you grabbed, but the backstep will work).
The swing on the sword is also enough to knock some enemies out of their attack animations, just like most of Raiden's other regular attacks. If you don't want to parry, you will need to know which to use (out of the sidesteps and the backstep) to guard against different kinds of attacks. The sidesteps will sometimes spin you nearly behind an enemy if you are soft/hard-locked on to the enemy and relatively close, as well, but I haven't played around with it enough yet to know exactly what causes this.
Inputting the analog direction for the left/right steps is relative to Raiden's facing position, not the camera. It's easiest to use 1 (down-left) and 3 (down-right) + jump + wide attack for the sidesteps (assuming Raiden is facing forward) since using just left or right can lead to input error. There is no forward step.
Is there a way to block bullets, I know it was mentioned somewhere but I cant remember where.
Like others have said, use ninja run, and Raiden will automatically deflect bullets. Projectiles like rockets can be cut in blade mode.