Yes, sauna suits are safe for the children, but don't use them in the sauna.
Sauna suits are not meant to be worn in sauna. You are supposed to be naked in there.
No! Sauna suits are very dangerous in the sauna. They interfere with your body's ability to sweat. If you're wearing a vinyl suit, they give off huge quantities of toxic chemicals that can injure you and your sauna companions. Plus the sauna suit is an insulator, so it's going to slow down the effects of the sauna. The best use of a sauna is wearing as little as possible, so most of your skin is exposed to the heat and your body can sweat freely.
The sauna suit is used to aid in the removal of excess water weight in the body. There is no scientific evidence that suggests the neoprene used to make these suits causes cancer.
Sauna belts don't work. So in general the answer would be losing money.
Sauna belt is safe, but it doesn't really work like it's advertised.
Yes, as long as you take care of hydration
You can buy a home sauna kit from http://www.saunafin.com/. You can also buy one from amazon.com, which has user reviews on the product.
Sauna twin is a product that makes you sweat, but disgraces the name of sauna because it has nothing to do with actual sauna.
In a Finnish sauna, yes. In a Turkish sauna, no.
In a Swedish sauna yes, in a Finnish sauna no.
Sauna World Championships are held in Finland, not Sweden. Swedish sauna is about 60 degrees colder than the Finnish sauna.