I think that you can still get brass balls as long as it didn't save after you used the Vita-Chamber.

I don't think you can turn them off, I've never seen the option to do so.

Dude, I love that GTA shit in your sig.

The option to disable the chambers should have been in the free dlc. since you are talking about brass balls ill assume you have already downloaded it.
Its not uncommon to come across a glitch that will cause the option to disappear. Nothing else should be affected by it disappearing and you should still be able to earn the achievement. (provided you load a file from before dying)

If Im not mistaken, you have to manually download the DLC, it doesnt download it automatically as an update, as its an optional free DLC. You can find it on XBL marketplace. There should be no reason its not on your initial settings screen or on your pause screen, it should be there.

As you are nearer to the start of the game, I would feel safer to restart and turn the option off, unless you are 100% sure you didnt resurrect before you saved. I am 80% sure that if you didnt save after you resurrected for the first time, you should get the achievement at the end.

Its an interesting question and one I am not 100% sure about. The achievement says that as long as you complete the game without resurrecting, you should get it so I am 80% sure you should be fine without having the DLC before. I would check the achievement websites for clarity. I normally go to http://www.xbox360achievements.org or http://www.achieve360points.com. If you dont get your answer, then I would feel safer restarting as youre nearer the start :). (the pains of being a achivement whore I know, we have all been there).

There are some tricks hidden in the area where that Big Daddy lurks that would allow you to kill it right then. It's still risky business tho!

been a while since i played, but i think i got him to chase me around some crates. He couldnt get a clear shot at me, so it wasnt too hard.

the crossbow later on will become key to killing big daddys.... until then, freeze or shock them, and use the shotgun. (also use telikinesis to throw their occasional bombs at you, back AT THEM.

The room with the turrets under each side of the boardwalk? Take out all the splicers in that room and the next, hack those turrets, go the next room and hack the rocket turret. Go back and wait until he's inbetween the 2 turrets, toss the canister, triggering the 2 turrets to attack him, then while he's taking them out, hit him with electric buck and draw him into the room with the rocket turret and take up position on the stairs near the circus of values. When he approaches the gatherer's garden use electric bolt to keep him still while the rocket turret does the dirty work. Even if he manages to take out the rocket turret he should be low enough to finish off with a couple electric buck or armor-piercing machine gun rounds.

You guys make me want to go back and play Bio-shock again. May be I will after finish up Ninja Gaiden 2.