Do I need to install new brake pads or rotors when I swap this in?

The knuckle assembly provides the mounting surface for your existing caliper. Whether you need new pads or rotors depends on their current condition—inspect them during installation and replace if worn.

What fasteners do I need to bolt this to my car?

You'll need the factory control arm bolts, strut attachment hardware, and tie-rod fasteners. These are standard items; refer to your vehicle's service manual for torque specs and bolt types.

Is the wheel bearing pressed on, or do I need to source one separately?

The bearing comes integrated into the assembly—it's already installed and sealed. You're not replacing or pressing anything; the knuckle is ready to mount as-is.