Do I need a special key or socket to install the locking lugs?

The locking nuts use a security key to install and remove — this key is included with the set. Once installed, the key is required to take them off, which is the whole point for theft protection.

Can I mix and match these with my existing lug nuts, or do I need to replace all of them at once?

You can use a combination. Install the 4 locking lugs on one wheel and standard nuts elsewhere, or run all 16 standard nuts if you don't need the security feature. Just confirm your wheel bolt pattern matches M12x1.25 before ordering.

Will aluminum lug nuts work with my brake dust or cleaning routine, or do they require special maintenance?

Aluminum anodizing is durable and handles standard wheel cleaning fine. Avoid harsh chemicals or wire wheels on the finish. They'll oxidize slightly over time like any anodized part, but that's cosmetic — structural integrity stays solid.