Will this knuckle need realignment after installation?

Wheel alignment should always be checked after replacing any steering component. The knuckle itself mounts at factory points, but a full alignment is the only way to confirm your suspension geometry is correct.

Does this assembly include mounting bolts or hardware?

Only the loaded knuckle assembly is included. You'll need to source fasteners that match your factory specification—check your service manual for torque specs and bolt sizes before you install.

Can I install this myself, or do I need a shop?

Knuckle replacement is DIY-doable if you have basic hand tools and a jack, but it does involve suspension work. If you're not confident removing and reseating steering components, a shop is safer. Either way, finish with that alignment.