sounds tasty. i have no experience with adding fruit to secondary so your guess is as good as anyone's. the kolsch i make has a small amount of honey malt added, just a few ounces. adds a slight honey aroma and flavor that's really great.
any extract beer you make will always be darker than the all grain version. extract is simply wort that's been boiled down to a syrup and carmelization will occur. then when you boil more carmelization occurs.
one thought i just had about the apples; you might want to think about removing the peels before adding. it's my educated guess that there are tannins in apple peels (just like grape skins and barley husks) and you might as well try to avoid getting tannins in your beer. keep us updated.