Will this bracket work with my aftermarket lower valance?

This bracket is engineered for factory lower valance clearance. If you're running an aftermarket valance, test-fit it before committing to installation to confirm no contact points.

Does this come with bolts and fasteners?

The bracket ships as the component only. You'll use the factory fastener holes at the attachment points — check your service manual for the correct bolt size and torque spec.

Can I paint this before installing it?

Yes. The aluminum accepts primer and paint well. If painting, do it before install to avoid masking hassle, then let cure fully before bolting on.