The apples would add a lot of simple sugars as well as tartness that would help dry out the beer and balance the high sweetness. However...
I really would not recommend adding actual apples at any point, especially not the boil. Why not juice them, or find juice to add instead? I use a standard juicer kitchen appliance to make my own cider every year. A half bushel will give you roughly 1.5 gallons. Also...
To make my own apple ale, which I've made numerous times and which has won awards, I brew a smaller batch of wort and then add the juice to make up the rest of the volume, in an approximate 2:1 ratio or 3:2 or thereabouts. My apple ale is sort of a witbier base but without coriander, as I find the WLP400 yeast gives off a pear/apple ester that complements the real apple quite well.
And like the others said..... man, that's really a LOT of crystal malt. With or without apples or apple juice added, it's going to be way too sweet I would think. Cut WAY back on the crystal, maybe to only about 10-12 oz total. This includes Carapils. Select whether you want Crystal 60 or Carapils, but there's no need to use both.