Will I get my money back if I´m not satisfied?  No problem. 

Is silk strong?
Yes, if you treat silk correctly it will last for long.

To wash in only 30 degrees, will the silk really  get clean enough? 
Absolutely, you should treat silk like wool.

Is it children labour? 
As far as I know it is not. The whole family works in the shop, I know the family personally and we have a very good relationship.