If I plan on using the stove later I do not release the gas pressure. By the time a meal is prepared the pressure is low anyway. If I am breaking camp I drain the tank back into the gas can using my filter funnel.
If there is still pressure in the tank and I want to empty it I just loosen the cap slightly. Another method would to put you filter funnel in the neck of your fuel can. Then point the generator into the funnel and turn on the valve. That will safely release any pressure. Again I would not do this around any open flame.
Suggest you pull maintenance on the old pump. A few shots of light machine oil into the hole along side the pump stem will do wonders. Then work it a few times. I then add some oil and work it some more. The pumps dry out in storage. It does not hurt to do this again when placing the stove into storage after a trip.
Be sure and drain the tank when you store it. The fuel attracts moisture and this will cause rust in the tank, Rust will be the death of the generator.