When the gall bladder contains stones , does that mean the gall bladder is not doing its work at all ? what if we remove the stones , will it be fine?

Not really: Gallstones can cause gallbladder pain or gallbladder attack. That doesn't mean gallbladder not working. Nowaday, gallbladder surgery mean taking gallbladder and stone out at the same time. The risk of taking stones out of it possible its that you can get more stone develop in there and had to go back and doing the same stuff again. Not worth it.