1. Yes, however as its an electronic handbrake, the efficiency of the brake is better than a cable operated ones.
2. Front discs yes, however rear brakes don't have much work to do and cool down rapidly.
3. This can happen with older cars, newer cars are either better maintained early on, or have good seals. Newer cars should be able to easily overcome 'seized' rear brakes by giving it some beans to brake the rust seal. Older cars will need their callipers looking to for either a 'remove, clean, degrease, refit', replacement or rebuild to overcome.
Some further points, if you leave your handbrake off when parked and it rolled away, then you could be looking at criminal charges if it resulted in an indecent (such as your car rolling away. In addition, you would most certainty invalidate your insurance
It could also make your car much easier to steal.
From the highway code:
It is also a requirement of the road traffic actParking (rules 239 to 247)
Rule 239
Use off-street parking areas, or bays marked out with white lines on the road as parking places, wherever possible. If you have to stop on the roadside:
•do not park facing against the traffic flow
•stop as close as you can to the side
•do not stop too close to a vehicle displaying a Blue Badge: remember, the occupant may need more room to get in or out
•you MUST switch off the engine, headlights and fog lights
•you MUST apply the handbrake before leaving the vehicle
•you MUST ensure you do not hit anyone when you open your door. Check for cyclists or other traffic
•it is safer for your passengers (especially children) to get out of the vehicle on the side next to the kerb
•put all valuables out of sight and make sure your vehicle is secure
•lock your vehicle.
http://www.legislation.gov.uk/uksi/1986 ... n/107/made
Leaving motor vehicles unattended
107.—
(1) Save as provided in paragraph (2), no person shall leave, or cause or permit to be left, on a road a motor vehicle which is not attended by a person licensed to drive it unless the engine is stopped and any parking brake with which the vehicle is required to be equipped is effectively set.
(2) The requirement specified in paragraph (1) as to the stopping of the engine shall not apply in respect of a vehicle—
(a)being used for ambulance, fire brigade or police purposes; or
(b) in such a position and condition as not to be likely to endanger any person or property and engaged in an operation which requires its engine to be used to:
(i) drive machinery forming part of, or mounted on, the vehicle and used for purposes other than driving the vehicle; or
(ii) maintain the electrical power of the batteries of the vehicle at a level required for driving that machinery or apparatus.
(3) In this regulation “parking brake” means a brake fitted to a vehicle in accordance with requirement 16 or 18 in Schedule 3.