I have booked it in for 11th of feb, I'm on a cruise so it's my first available day.
I told them its got low coolant temp about 79-80c average, engine has a misfire when it's been driven hard or for a long time, which I don't class as normal. It can't be the dpf regen as I have not driven far inbetwen. Our vans when doing a regen you can't tell apart from extra heat from under it! It's also got sticking hand brake cables and finally the battery is pretty poor. Struggles to start.
As for the idling I don't worry about that I can't see as it will cause that much more damage than say someone who drives straight off. I only do it sometimes as it takes so bloody long to warm up before I can boot it! It takes a good 10 miles otherwise, so I let it warm slightly to bring coolant and oil temp up in order to drive abit harder. It's never caused me any problems I previous cars, I also change oil every 5k so any diesel that past the rings will be drained off.