Will this work if I'm running an aftermarket front bumper?

This bar is engineered for OEM Accord bumper mounting geometry. Aftermarket bumpers often have different attachment layouts, so test-fit before final commitment. You may need to verify alignment with your specific bumper design.

Do I need to remove the bumper cover to install this?

You'll need access to the mounting points behind the bumper fascia, which typically means removing the bumper cover or at least unclipping the lower sections. It's not a behind-the-bumper-without-removal install.

Should I paint this before or after installation?

Paint after installation once it's mounted and verified for fit. This prevents paint damage during handling and ensures a clean final finish. Sand lightly and apply primer-surfacer before your color coat.