Do these come with the wheel studs?

Yes, studs are pre-installed on the hub. You'll use them to mount your wheel and rotor assembly directly.

Will I need new axle nuts or any hardware to install these?

You'll need an axle nut to secure the hub onto the spindle. Refer to your service manual for the correct torque specification—don't guess on this one.

Are these sealed bearings, or do they need to be repacked?

These are sealed bearing units—no repacking or maintenance needed. Install and forget; they're built to last the life of the hub.