First, a general overview of what I'm trying to do:

I intend to convert a large number of music files to low-bitrate mono mp3s for use with my CD player outputting to an FM transmitter and sending that signal to a small FM radio earbud. (Boring college classroom entertainment)

I intend to be getting the volume level as loud as possible without noticeable clipping, compress the dynamics so I don't have to worry about volume controls, and preferably, do all this in foobar.

Questions:
1. Does the preamp come into play when using the diskwriter? If I cannot use the preamp with diskwriter, is there still a DSP version? What else could I use?
2. The dynamics compressor has peak limit set to 100% I assume this means 89db (no clipping). If this assumption is correct, will it effectively lower the volume that I intentionally raised with the preamp, or will it raise the volume to 100% and THEN be raised another Xdb by the preamp?

err... *bump*? Anyone?

Do either or a combination of

1) Not use Preamp.

2) Use dynamics compressor with peak limit set to 100%. This has nothing to do with the 89dB ReplayGain reference level. 100% peak limit is exactly what it says: boosting to full scale.

or

1) Use preamp.

2) Use advanced limiter.

The second allows you to get more loudness, but will increase distortion. Experimenting with parameters recommended.