I have a 98 cavalier, 2.2L, automatic

I have 3 problems:

1) When the car is first put into drive, I get a loud rattle, but only when Im on the brakes. This continues to happen for the first couple of times I stop until the car warms up a little bit. After about 5 minutes of driving or so, the problem disappears. This only happens while im in drive, and only when im stopped, and only when the engine is cool. If I start up while the engine is still warm, I have no problems. If I put it into neutral while stopped, no rattle (my current solution)

2) When I shift into drive, it usually is accompanied by a bang. thats the only gear I have a problem with, as there is no noise and it goes nice and smooth into reverse, neutral, etc. I checked the tranny fluid and the level is fine, but somewhat brown. I was thinking of flushing it, but im not sure if that would solve this problem.

3) When I first step on the gas (off of every stop, most of the time im driving), I get a noise. Its hard to categorize the noise, but kind of like a low rumble, then it stops when i pick up some speed. A friend of mine said it could possibly be the CV joint, but im just curious as to what other causes could be (not that this description is that good :frown: )

Any input would be greatly appreciated, especially on #1