you cant cook on a kelly kettle, despite what they sell for it. leaving it boiling will blow all the water out of the kelly before it starts to melt, and using the base alone loses the draught effect of the kettle. ive a woodgass stove with a fan in it that runs off a solar charged battery pack, its never run out of charge!
Yes you can, you'd just have to be desperate and have something tinned or boil in the bag. Boil it up and tip the water into a pan. Drop the tin of beans into the the hot water (top part off) and start another lot going but with your cross beams in place. Once the fire is back up, get the pan on the beams and heat further. Top off the water in the kettle as required. After about half an hour you have luke warm beans.
Given wet wood is PITA with the Kelly kettle, as a back up, hexamine tommy cookers are smaller and lighter.
I built one of those wood stoves with a 9V computer box fan. It worked, but it's like cooking with the KK, slow and luke warm. Simply not enough energy in wood unless you look at pellets. If you are carrying pellets why not carry a proper stove?
Andy