How can I play a CD and rerecord with changes in the volumn of certain parts of the input?
Either play the CD and record it into Audacity - or rip it as a (set of) WAV files and load those into Audacity.
Then you can vary the amplification along the timeline of the track(s) by using the Envelope tool (icon is two little white triangles pointing to a little dot, with a blue line running through). You can drag the blue line up and down at points the you create to vary the amplitude.
Note that you cannot do this in real-time while you are playing your CD as Audacity does not apply any effects in real-time.
No, but you can adjust the recording level using the Windows Mixer during the recording.
(I fail to see what this has to do with “forum issues”)