Will this lip scrape on speed bumps or driveway transitions?

Ground clearance depends on your suspension setup and how low the lip extends. Measure from your current bumper to the ground, then compare that to the lip's total length before installation. If you run lowered springs or coilovers, plan for clearance accordingly — FRP is durable, but repeated scraping will eventually show wear.

Does FRP flex in the wind at highway speeds?

FRP is a rigid plastic composite, not rubber or foam. It won't oscillate or bounce. However, it is slightly more forgiving than metal in minor impact situations — it can absorb a light tap without denting, though harder collisions can crack it. Normal highway driving produces zero flex.

What do I need to do to prep this for paint?

Sand the primer surface with appropriate grit sandpaper and wipe clean. FRP is ready to accept primer and topcoat without sealing or special bonding agents. Once sanded, follow your paint system's manufacturer instructions for primer and color application.