Thats such a interesting idea (why is it that I search and search for added/missed things like that and yet always miss them

). You are so right, it would have taken substantial effort to include these supposedly meaningless actions and that they do seem rather out of context - I think that you are right, there could be something more to it.
I searched for any metaphorical meanings that may be connected to the series/the war/ trust etc, but I'm not entirely sure of the results (so please excuse my somewhat horrific attempts at analysing what I found

)
The last quote is quite possibly the most relevant if you want to skip to that 
QUOTE
According to a popular legend, Isaac Newton, upon witnessing an apple fall from its tree, was inspired to conclude that a similar 'universal gravitation' attracted the moon toward the Earth as well (this legend is discussed in more detail in the article on Isaac Newton).
This could possibly be related to Lupin/'Moony' with the moon connection. However, I'm not entirely sure about any connection with Draco - perhaps these two characters may be drawn together, as well as Dracos' being Green for Syltherin it could also be Green for Earth (I'm clutching at straws aren't I?)
QUOTE
This stemmed from the fact that teachers during the 16th to 18th centuries were poorly paid, so parents would compensate the teacher by providing food. As apples were a very common crop, teachers would often be given baskets of apples by students. As wages increased, the quantity of apples was toned down to a single fruit.
This could perhaps be related to the fact that Lupin is so poor and is a teacher. conversely, Draco has considerable wealth (well his father does anyway

), given his selfish nature, it could stand to reason that he would not give to the poor - However, now Lupin is in a position of power as Draco has had to leave his wealth and status behind as he flees for his life (from both the order and the death eaters, having attempted and failed in his task to kill DD)
QUOTE
Swiss folklore holds that William Tell courageously shot an apple from his son's head with his crossbow, defying a tyrannical ruler and bringing freedom to his people.
could this perhaps link to the freedom from a certain snakelike tyrannical leader, both for Draco (LV certainly has a hold over him) and for Lupins people (either the Order or the opressed Werewolves)
QUOTE
In Norse mythology, the goddess Iðunn was the appointed keeper of apples that kept the Æsir young forever. Iðunn was abducted by Þjazi the giant, who used Loki to lure Iðunn and her apples out of Ásgarðr. The Æsir began to age without Iðunn’s apples, so they coerced Loki into rescuing her. After borrowing Freyja’s falcon skin, Loki liberated Iðunn from Þjazi by transforming her into a nut for the flight back. Þjazi gave chase in the form of an eagle, where upon reaching Ásgarðr he was set aflame by a bonfire lit by the Æsir. With the return of Iðunn’s apples, the Æsir regained their lost youth.
I'm really not sure about this one, but maybe the terms 'Keeper of..' and 'Giant' could point to a significant link between Draco and Lupin and Hagrid. Perhaps if you considered the apples as something else like Harry or a Hocrux - then that may have been stolen consequently causing the aging (or hinder the stoppage of death) of LV or well... I don't know really (I got lost with the names

) but this link sort of goes with the idea that apples may represent immortality
QUOTE
Apples were once considered to be the food of the gods; if you cut an apple in half crosswise, the center is revealed to be a five-pointed star. Apples and apple trees are symbolic of the guarantee of immortality in Irish tradition
(so maybe Draco and Lupin will be fundamental in hiding a hocrux from LV)...
QUOTE
The expression "apple of the eye" has biblical origins, and means the pupil of the eye and something or someone that is very precious and in need of protection. (Deuteronomy 32:10, Proverbs 7:2, Lamentations 2:18, Zechariah 2:8)
Keep me as the apple of the eye, hide me under the shadow of thy wings. (Psalm 17:8)
Maybe Lupin will protect and/or hide Draco
QUOTE
Traditional Christianity generally regards the apple as the fruit of the Tree of Knowledge, which Satan tempted Eve with in the Garden of Eden. Since that time, superstition has dictated that to eat an apple without polishing it first is a challenge to Satan.
this was an interesting one, as I seem to remember that Draco polished his apple on his shirt first (I maybe wrong though) - perhahs this is symbolic of Dracos' pact with LV and Lupins secret (fluffy) missions against LV
However, this is the one that struck a chord with me (from
http://www.experiencefestival.com/a/Apple/id/35104)QUOTE
To dream of ripe, sweet, red and green apples is a promise of well-deserved reward and shows the achievement of harmonious balance in your life. If the apples dreamed of are green and bitter, it indicates that you could face a loss through your own foolishness and fickle friendships. Red, ripe apples denote true, dependable friendships
Lupin has already been shown true friendship in many ways, through the marauders learning the Animagus spell and Tonks and the faith DD showed in him etc. But it is also spot-on that Draco faced a lss through his own foolishness.The last one is the closest I could find, admittedly the rest are a bit weak but there is definately a lot of symbolism behind Apples and it could shown an important link between these two characters, Good catch Michelle Dessler (sorry I couldn't be of more help, and that this post was so long, but you definately got me thinking about apples

)