Would answer all your questions, but unless you are in the industry already and have an employer funding your training, doesn’t help.
I am very rusty and never used to spec much anyway, but from waht I can recall
Most of the time you would pull from the front wheels. Most cars at least have a low front and more ground clearance from the rear axle to the rear of the body.
Rear wheel drive / 4wd bring issues, so may involve disconnecting the prop shaft. I think there will be road going dollies available to allow all wheels to be off the tarmac in transit, but I haven’t used or had them before. Similar situation with a RDT.
The spec will pivot centrally so I don’t think there is a need for the steering lock to be either on or off. If you were in a situation where you rear lift a vehicle then steering lock on and ideally tie off the steering wheel nice and straight…
I’m not sure what you mean by wally lights, you should use a trailer board or cordless rear lights on the back of the vehicle in transit. If you mean strobes and beacons I would say not while in motion, but there might be a case to say keep them on.
You would secure the wheels into the spec, with straps going round the circumference or behind the top of the wheel to points on the outer corner of the spec frame.
You would expect to have a couple of breakaway chains to secure to the chasis somewhere handy in case something goes wrong.
The spec arm has both a raise lower control and extension from the back of the truck, bringing the arm back on too close would mean you get contact with the casualty vehicle on a turn as the angle closes up.
These have come out since I left the industry, so I have not used one but see them around.
My old truck with a JerrDan fitout you would add the second bars in manually to assemble the lift at the point of loading.
The big question though is should you have C&E to use the spec legally?
I have heard a second hand anecdote from a good source about someone being pulled in but no action taken when they checked on the weighbridge as the weight on the back wheels of the casualty was under 750kg. The fact that AA routinely train their tilt and slide drivers to C&E would suggest there are plenty of times where you should have it to be legal though.
