I had it on the rs ra and was good for warming up, as it had a little piston slap at cold that disappeared within a few minutes, so would start the car and by the time I'd locked up the house it was nice and quiet and the oil pressure was good. Due to its age I liked to make sure she wasnt heading out the hate stone cold.
As for leaving in gear and the remote starter I'm not sure as I was always paranoid about leaving it in gear, and always had it drilled into me to leave it out of gear unless on a hill. You could wire up a micro switch to disable it when in gear.
I also loved to hear it rumble to life just before leaving the office.