I am in the same boat as you, starting out new in the midst of all this chaos. A lot of your questions are a little up in the air as they just had a hearing and will be passing final judgements soon. but I've done tons of reading this last week and will answer you as best I can:
1. I'm not sure if you can re use the labels. I think you could. the only thing that I wonder is if those labels and the ink printed on them is cpsia compliant. if they are adult sweater than they most likely haven't been tested by the company that made them...and annoyingly enough the labels materials must be in compliance too.
2. your label needs the name of your company, washing instructions, fiber content and country of origin in which fibers came from (USA or imported is enough info I believe). I dont believe it has to be a seperate label but it can be if you want, but you must also have the tracking info. when it was made, batch # type of stuff.
3. for now cottons, wool, etc (theres a list marked table B at the cpsc website stating what is currently exempt) can be used without testing...however come january of 2012 if they haven't changed the laws to better suit small manufactureres and crafters like us, then those items may not be exempt. that's part of what is up in the air right now.
isn't this stuff frustrating?!?! I have a 19 month old daughter and of course I want her to be safe, but blanket laws like this that cover a general distance are just plain ignorant!
please anyone, correct me on all of the above if I'm wrong, but as I read this is what I believed it to be saying.
you also need to be careful about the buttons, velcro, zippers, etc. sigh.