Yes, roller skating is safe for your kid. All the concern about adjustability and age-bound designs are for the safety of your kids. That is why you should become aware of what the thumb rule of kid skating says. You should go by the specified kid skates endorsed by the reputed brands.
In addition, you need to maintain the age limit and escort your little one on the rink and park up to he turns 8. First, one or two weeks are crucial enough not to let them skate alone.