These are primarily marketing gimmicks for sensory appeal. There is little scientific evidence that gold or crushed diamonds provide any anti-aging benefits beyond the temporary glow they might impart. Focus on the active ingredient list, not the glitter.
Yes. Beards can protect the skin from sun damage, but the skin underneath needs cleansing, hydration, and sunscreen to prevent dryness and aging. Use beard oils with antioxidants.
Focus on humectants (hyaluronic acid), emollients (ceramides), and peptides. Gentle exfoliation becomes important to remove built-up dead skin cells that can make wrinkles appear more pronounced.
Start with a clean face, apply a antioxidant serum, follow with moisturizer, and always finish with sunscreen as the last step before makeup.