Re: Unnecessary points of failure
the cooker (for safety) shouldn't be switched on without a person in the house
Have to note here that all the electric ovens (and a few of the gas ones) that I've used over the last 40-odd years have had delay timers. The idea being that you could prepare a casserole or a pot-roast or something in the morning, leave it in the oven when you go out and have it turn on two or three hours before you return.
Or you prepare the turkey the night before Christmas and then instead of getting up at 5am to put it in the oven, the oven turns itself on.
I think in all that time I've used that function once. Maybe twice. Christmas? It'd have to be a ginormous turkey to need seven hours of cooking, and with the kids waking up at 6am anyway, bit pointless.
That's ignoring the wisdom (or otherwise) of leaving uncooked food at ambient temperature for that length of time.
M.