ice in the bottom of my LG freezer

[derrellsimpson]

hello.
i have a 14-15 year old LG LRTN22312SW refrigerator with freezer on top.  i have a LOT of ice accumulating on the bottom of the freezer and water dripping down into the fridge.  i have pulled the back out of the freezer and the coils aren't iced over and the drain seems clear.  i poured water down it and heard it splash in the pan at the bottom (I hung a wire extending down the drain hole connected to the heating element just  in case it was freezing over.  There is no leak from the ice maker which is currently turned off.  the water seems to be seeping in from the bottom seam where the back panel meets the bottom of the freezer.  i noticed that the insulation on the back of the freezer panel i removed was wet and frozen.  i cut off the bottom inch or two of the insulation that was completely frozen.

2 questions:
1.  what the heck is causing the water??  is it condensation on the inside of the back panel dripping down?
2.  do you think removing ALL the insulation on the back panel would cause a problem?

thanks in advance for any help or tips you might provide.  I'm REALLY trying to not have to buy a new unit.

DS