You can find a summary of all studies on grounding here

As often and as long as possible. Being grounded was and is the natural state of the human body. We encourage you to regain this natural state with our products and skin contact with the ground outside. As you spend most of the day either at your desk or in bed, we have designed our products with these two main use cases in mind.

Earthing", defined as "the practice of electrically grounding the body", is not esoteric at all. It simply deals with the natural electrical state of the body, which by evolution should be mainly neutral. The effects of grounding the body have been researched by science for 20 years in over 30 studies. If people attach a symbolic or energetic meaning to the practice of electrical grounding and its biophysical effects on the body, this is due to individual belief systems and should be considered separately.

No. The pins of our plugs are made of non-conductive plastic. There is only contact to the earth clips of the socket. With regard to a lightning strike, there is just as much danger as if you were to take a shower or touch the heater during a thunderstorm. Water pipes are also earthed. Nevertheless, as with all electrical appliances, we recommend unplugging our products if the storm is very close.