As far as the aluminum goes, I can't see the weather hurting it. But if your mast or boom is near the ground, it becomes a potential site for bird, rodent, and insect infestation. Same goes for your boat. Also, your lines will continue to deteriorate in the elements. After I bought my boat last year, I found birds' nests in the mast and boom. Yuck! The lines were nasty! I replaced them, and I will seal the ends of the boom and mast this winter, and I will cover or wrap any exposed lines, so they stay cleaner. I admit I don't want to de-rig the mast to launder the lines. Oh, and throw some moth balls in the boat. I am told they work to keep mice out. Maybe others will add more info!
Thanks,
Andrew