The floats are stuck, or there's a piece of crud between the needle and seat (this is what opens and closes as the floats go up and down).
I have a feeling the idle problem and the fuel problem may be from the same cause. You'll have to remove the bowl and check the needle and seat carefully for gunk and/or wear. If they're worn, you'll have to replace them.
If the needle and seat look okay, check the floats - sometimes they'll get holes in them and fill with fuel - then they sink!