I do plan on giving this another shot. I do feel that my mistakes were:
1. not letting the icecream refreeze over night in pan.
2. not freezing the actual cake part after cooling.
3. using whipped topping instead of whipped icing or buttercream.
4. airbrushing the whipped topping.
Hopefully by rethinking these steps I should have a better success next time around. Thank goodness the cake was not for a placed order or I would have been in a panic! Its still was delicious even though it didn't look pretty.