The range is wide open. My son is 1 1/2yrs and is using it with the seat. My daughter is 4 and still loves to ride her scooter without the seat of cours. I would say she can use it another 2-3 years.

unfortunately have no idea. was a gift

yes, everything is included

Up to approx. 2-2 1/2 years old.

No, the manufacturer does not offer an enlargement for the footrests.

Sì :)