Boss music in games is a big thing to me, in Demon's Souls the boss music was meh not to amazing, but Dark Souls...man really sets it up.

I just got to the end of the PAINTED WORLD, but I didn't bother killing the boss because she didn't attack me! Will I be missing anything important leaving her alone?

Also just beat the bed if chaos boss, I'm sure I'm nearing the end now As ive also defeated the four kings and I've just been defeated by the seath, by I don't think you can Beat him first time can you?

I also discovered this when i attempted to kill the red dragon. it took me like 70 attempts (i know because of the ammount of arrows i used to lure it down) but i amassed so many souls in that time, and i managed to kill it. for a measly 10,000 souls.

not that it helped much, i'm now in Blighttown. this area is just like Valley of Defilement in Demon's Souls. but that swamp at the bottom is ridiculously hard, the enemies seem to keep respawning?

You'll miss her souls, which is required to create an unique scythe, and her tail drops an unique dagger.  Plus, there's a trophy for defeating her. 

You can't beat Seath the first time you face him (at the top of that large stairway after coming from the elevator), since he's basically immortal. Even on the normal fight, if you don't know the trick to it, you can't damage him as well.

@A203D - The mosquito enemies keep respawning as long as you're within the range that they can see you. They won't trouble you if you go a bit further than their spawning point. To be honest, I find the dart enemies much more annoying, since they can put the Toxic state on you on an instant, even with high poison resistance. 

Is it possible for a Sorcerer class to train Pyromancer spells? I accidently killed the Pyro trainer in the depths trying to free him from the barrel. The 2nd Pyro trainer in Blighttown says I need to give her something.

You mean Quelaana (a black-robed witch)? Odd, she usually only appears after you have a Pyromancer Flame +10 in your inventory. I think that you won't be able to get her pyro spells (and you've already missed a couple by killing Laurentius) until you do. 

There's a third pyro trainer, once you defeat Quelaag. Going down the stairway near the bell there, there's a hidden path on the right side of the bottom of the stairway, which is protected by a talking egg guy. If you say yes to his question, he'll let you through and you'll be able to get a Pyromancer's Flame and upgrade it to +10, allowing you to talk/interact with Quelaana.

And yes, sorcerors can train Pyromancer spells, as can any other class.

Hellkite Dragon fell rather swiftly to my tank/melee build on NG++ XD. Flash Sweat + Iron Flesh = Insignificant amount of damage from his breath attacks.

What bow do you need to use the dragonslayer arrows? Also is it possible to buy the arrows I'm sure I might of seen them in a blacksmiths inventory.

It's the Dragonslayer Greatbow. It's found on a secret path on the top of the area prior to the boss fight. There's a window that's shattered and you can go outside to a ledge, follow that ledge and you'll see a treasure on the left side. You'll either have to roll or jump to get there (it's on a fenced area) and if you miss, you'll be back at the entrance guarded by the two Giant Soldiers.

It's possible to buy them, but they're very expensive, at 500 each.

The only covenant that sounds really annoying is the Blade of the Darkmoon. I'm assuming I have to invade and kill 10 people. That's probably going to take forever.