If you mean Station bred as in the type of horse bred in New Zealand, then yes they can make good jumpers. They may be limited in how high they can jump due to their stock horse conformation, but they should make good lower to mid level jumpers with the correct training.
Stationbred
No. you should be off the jumper by 10 years old.
yes
The proper way to use jumper cables to boost a low/dead battery: (1) one end of positive jumper cable to "dead" battery; (2) opposite end of positive jumper cable to "good" battery; (3) one end of negative jumper cable to "good" battery; (4) opposite end of negative jumper cable to GROUND on "dead" vehicle. Remove jumper cables in reverse order.
Some good locations to purchase jumper dresses are Ebay, Nextag, Amazon, One Good Thread, Angelic Pretty, and Asos. Two more good place are JcPenny and Boohoo.
Yes, it seems very nice.
grasshopper
Having knees...
Most likely when the battery is no good anymore.
leggings/tights with a big jumper :)
Ensure jumper cables have good connection
No. EDIT: It really depends. A full-blooded Clydesdale is unlikely to be a good jumper, as they are heavily built and very compact. They are made more for pulling weights and using their strength for working. However, when crossed with Thoroughbreds or Warmbloods they make very good cross-country horses as they are big and strong, but also have the speed/leanness of a competition horse. New Zealand, my country, has a breed called the "Stationbred" which is largely based on Clydesdale and Thoroughbred blood. Horses from this breed are bold and definitely look Clydie (they often have white faces, large leg markings and plenty of feather). The Clydie influence gives them the size and strength necessary to make good hunting horses.