Definitely a dutch warmblood. Thoroughbreds are more suited for things like racing or eventing because of their body type.
It is a horse, normally used for horse racing, whose pedigree can be traced clearly to acceptable ancestry. Specifically to one of three stallions: the Darley Arabian, the Byerly Turk or the...
A Thoroughbred is a registered breed, while a Thoroughbred X (literally 'Thoroughbred cross') is a mixed breed with Thoroughbred blood present.
Impossible to answer without more information.
Thouroughbreds are specially bred racehorses which are tall and built for speed. They are one of the oldest and most pure breeds of horse.