Do I need to drain and refill coolant, or does this come precharged?

You'll need to drain your existing system and refill with fresh coolant. The radiator itself arrives empty. Follow your vehicle's service manual for coolant type and capacity.

Will the factory hose clamps and connections fit, or do I need new hardware?

Factory hose clamps reuse directly on the OEM connection ports. You may want fresh clamps if the originals show wear, but new hardware isn't required for installation.

Does this mount the same way as the original radiator?

Yes—factory mounting tabs and bracket points are identical to OEM. If your original bolted in without modification, this one will too.