I won't cook inside my tent, and although I could probably cook in the vestibule with the flaps open, I haven't--prefer to cook on a table instead of on the ground, and I think the heat of the stove if it was on the table in the vestibule would be too close to the fabric.
I do use my Mr. Buddy tent heater inside the tent (not too useful to heat the tent if it were outside the tent!

), but I'm very careful to keep it away from the sides of the tent. That's one of the benefits of having a tent that is larger than necessary--there's a lot more floor area to allow safe use of the tent heater. It's very stable, so it's unlikely to magically tip over by itself. I don't leave it on while I'm asleep, although I do leave the pilot light on so that it can be started up by just turning on the valve in the morning. I just reach over to the heater, turn it on, and 20 minutes later it's pleasantly warm inside the tent--lots better than getting out of a warm sleeping bag into a cold tent to get dressed!
Cary