To clarify the rubber door seal is worn, if this is the case it will need replaced. You can buy replacement door seals here, if you dont change the door seal you will start to find the fridge freezer is overworked to keep it cool, which costs more to run it, increases the amount of frost in the freezer and generally not a good idea to leave.
With regard to the warm of the fridge, this is most likely heat transfer from the compressor (motor), all electrical appliances pose some degree of fire hazard, since its not hot to touch, and assuming you have the correct fuse in the plug, I do not feel you have anything to worry about.
My suggestion would be change the door seal for around £30, ensure there is good ventilation at the back of the fridge for the heat from the radiator to escape from, and monitor it over a few weeks. If the fridge freezer doesnt get down to the correct temperature then I would have a re-think.