Can these planet artifacts be used even when the birth chart shows no defect?
Yes. Without a dosh they simply add energy. Nobody would refuse if God offered an exalted Jupiter, Mars or Saturn in their chart, and decorating with the items that represent such planets raises energy in the same way. Energy never becomes so much that it causes harm; how the gain is used is the person's own responsibility.
Related questions
Are the quartz trees sold today good to keep?
Yes. They mostly carry natural quartz of different colours, and they are far better than plastic decor, so they can be kept as showpieces in the interior.
As an interior designer, clients choose their own colours and I cannot check their planets; should I give a remedy or try to convince them?
Do not try to convince anyone. People mostly like the colours that match their own planets. If a client chooses an anti-element colour and their kundli allows it, never stop them; it will bring them benefit.
How do we choose a direction when no planet in the chart is exalted and several planets sit in one direction?
First choose the direction of exalted planets. If none are exalted, go towards the direction where the benefic planets sit: Venus, Mercury, Moon and Jupiter are benefic, while Rahu, Ketu, Saturn, Sun and Mars are malefic. Then use the interior items, seed mantras, artifacts, statues, trees, colours and symbols, to strengthen the planets that are not exalted.
How should a chart be read if no planet is exalted or debilitated?
That is not a problem. See where the key lords sit: for example, a lagna lord in the 5th house shows that life progresses through children and knowledge. Check its degree and strengthen it. The lagna lord, 5th lord and 9th lord, if not debilitated, can be strengthened through their gems, metals, colours and grains for all-round growth.
If one family member has a planet exalted and another has it debilitated, should that planet's items be kept in the interior?
Decide room by room. In your own bedroom use the materials of your exalted planet and not of your debilitated one; your daughter's bedroom is designed from her kundli. The house facing and common areas such as the drawing room and kitchen are decided from the grih swami's kundli. Many people make the master bedroom in the South-West by default, which is wrong when Rahu is debilitated: such people suffered there and got very good results after moving to another direction.
If the Sun is exalted in the 10th house, should the South also be improved, or should Sun items go only in the East?
Sun items go in the East, but they can also go in the directions of the friends of the Sun; one colour or one showpiece is not restricted to one place. That is why the colour combinations of friend planets were given.