I wouldn't recommend piling fruit around the base of your plants, I think it would attract too many bugs, insects, etc etc. I do a lot of vegetable gardening and i know that things like fresh grass clippings are not good to spread around as they will actually use nitrogen thereby denying it to your plants. It's the initial breakdown of the plant material that is causing this, I think fruit might have the same cause/effect. If you are thinking of dumping a bunch of old fruit at the bottom of you planting hole I don't think that would cause a problem, I would suggest putting a layer of soil between the fruit and the transplant.
I am not an expert. However, I think some fruit in the hole before transplating(cover it with some soil) might help some. The pilgrims used to throw a fish in the hole before planting and it was fine. I'm not sure if it matters if it is fruit or a fish
no, do not put any rotting stuff around or under your plant. Let it decompose first (compost) and then use the soil.