Music stream recording and format conversion(HowTo minimize downgrading of the audio)

[Iggy64]

I have some fundamental questions concerning audio stream recording.

Recording:
Most of the internet radio I enjoy streams mp3 at 128 kbps. I capture the streams using the StreamRipper plugin for Winamp. I assume that Streamripper is simply saving the mp3 as sent by the broadcaster; it is not converting from mp3 to something else, and then back to mp3. Is that a correct assumption?

Another option is to use something like Audacity to capture streams. The problem I see with this is that Audacity captures the stream from the sound card as its own proprietary .aup file. That is, it first decodes the mp3, then saves it as an aup file. To produce a playable mp3, I have to re-encode to mp3. I have always been taught to do the least possible amount of decoding and re-encoding, to minimize downgrading of the audio.

Splitting/Trimming:
If Streamripper is unable to cut the stream into individual mp3s (non-Shoutcast stream, for example), I use a direct mp3 editor, because that lets me trim the mp3s without converting decoding and recoding. Again, I presume this introduces the least corruption of the mp3.

Do I have all/any of this straight? Do some recorders capture the streamed mp3 directly, while others actually decode and re-encode? And do the latter type of recorders degrade the audio through those extra manipulations?