I cook in the "bell" porch of my wee tents but they are well ventilated. It has usually involve boiling water for coffee as I lie in my sleeping bag ( or defrosting boot laces).
I wouldn't cook in the inner of any tent or any part that has a fitted flysheet. As for my cotton tent, I wouldn't want food splatters, fatty steam on it so would cook under the tarp.
------------- Hypercamp Alaska
Vango Force 10 mk3
Vango F10 Helium 1
Coleman Cobra Pro 3
Coleman Cobra 2
Naturehike Star River 2
Eureka! Solitaire
Dutch army goretex bivvy bag
I agree about common sense - just be aware of the dangers and the solutions and all will be good.
Bear in mind that modern nylon/polyester tents are less breathable than cotton or polycotton canvas.
I use the porch for my Kalahari Elite 8 as a kitchen area. It doesnt have a sewn in groundsheet and isnt sealed to the tent so has plenty of ventilation (whether I like it or not!).
Perhaps for anyone unsure - just take along a Carbon Monoxide detector? They are tiny and take up no room.
It's also really important that people observe the safety instructions - like never using a too-big pan in one of the little canister / 'suitcase' stoves, and never using two side by side. (both will cause flames to be too close to the gas canister, causing explosion).