Jade is not true or false in my world view. Jade is a stone. If you can tell the truth from the false, there will be some truth, but not in Thailand.
You can't tell the truth from the false only by a few photos. You can find a shop selling this kind of jewelry and a knowledgeable master to help you identify the authenticity, but since your friend bought it from Thailand as a gift, he won't buy it fake.
4. Gallery is one of the two major jewelers in Phuket. All products have passed ISO certification, which is true in theory. If you are in doubt about the quality of gems, you can go to a local jewelry appraisal institution in China for jewelry appraisal.
5. There are only two places in Thailand where you can get a big certificate, which is more formal. Small card is hard to say. Those who really make jewelry generally don't recognize small certificates because it is too easy to make fakes. I don't mean to hurt you, but the crystal you bought should not be fake, but the quality and price definitely don't correspond. Where else does the tour guide's rebate come from?