Compression problems - volumes wrong, and "pumping"

[Mahalo]

Compression is a WONDERFUL thing, but it can also be very disruptive.

Combi Killer Gtr uses a Wah compression for that amazing guitar sound, the problem is these tracks are just too loud, but there is no way to turn them down.

The drums are at maximum volume already but I can find no simple way to hear the hihat above the compressed guitar. Reducing the volume of the guitars does nothing, also velocity slopes are completely ineffective, amazing but true, compression does that.

(NB: the original factory setting cuts the hihat, extend the drumtrack keyzone and solo the drum to hear it, then add guitar and it is gone!)

There should be an output volume on the compressor but everything I tried altered the tone or lost the effect or did nothing.

SECOND COMPRESSION PROBLEM

Somewhere in my recording here, the volume suddenly JUMPS LOUD. It is an artefact of the compression settings. Listen at around 50 seconds

http://soundcloud.com/microkool/libertango


When I play this live, it happens arbitrarily at any time, or not, clearly it is "pumping" and needs adjusting, and the sensitivity of the keyboard to velocity is incompatible with the compression but I have no idea how to correct it, I did not pay attention when we did that topic at music production college... I found the magazine articles and oline advice confusing, anyone know which of the Compression parameters I should adjust to avoid "pumping"