#1
been playing for 5 years, but i really suck for someone playing that long. consider me beginner intermediate.

what are some popular thrash/heavy metal classics that i can learn the whole song that arent too difficult?

i know all of war pigs except the solo
i know all of one except the last solo
im learning master of puppets

~Nick
#2
Venom - Black Metal
Celtic Frost - Eternal Summer
Sodom - Agent Orange
Slayer - Tormentor
Mercyful Fate - Desecration Of Souls
Candlemass - Under The Oak
#3
Judas Priest - Breaking the Law
Megadeth - Symphony of Destruction (rhythm, good luck with the solo!)
Metallica - No Remorse

Keep shreddin.' I learned pretty much only classic Metallica when I first learned. I just wrote an ebook on it actually, you can grab it for free at my website, linked from my profile.
#4
I do not presume to know what the artist had in mind when he wrote this song however music speaks differentially to every person, that said, I believe it is about a man talking about a woman with whom he was obviously in love and who in one of those "I need to find myself, find out who I am etc etc." moments, left him. Im sure most people have been trough that, and then when she "grows up" or gets fed up with whatever she was doing, partying, working etc.