No, these are ritual and decorative vessels. They are not certified for food or drink contact.

Yes. Burning incense, herbs or charcoal should be done in a well-ventilated space, away from combustible materials, and never left unattended. Charcoal and other solid fuels can also produce carbon monoxide, so this is one area where “ritual atmosphere” still needs ordinary fire-safety common sense.

Not necessarily. Copper naturally darkens and develops surface tarnish through exposure to air, moisture and handling; this is normal rather than a defect. Be cautious with metal polishes on antique-effect pieces, as aggressive cleaning may also change the intended finish.

Yes, particularly if they are stored damp or left in a moisture-prone environment. Keep them dry, wipe away moisture promptly and avoid leaving them soaking in water. A little sensible care will prevent most problems.

They can be considerably heavier than they look. Check the individual product weight before deciding where to merchandise them, use sturdy level shelving and keep heavier pieces away from shelf edges or positions where customers could easily knock them down.