...forgot to mention.

Yesterday I added track-gain as a knob at the top all audio channelstrips. 
It's not affected by automation but stored with the song. The value shown is multiplied as is with the current value, perhaps it should be logarithmized...somehow??

Florian, we talked about adding this to midi tracks also but upon working on it I realized that we can something similar. The way I understand it, it's even better suited than a gain parameter.
In the midi track info there are two parameters, Velocity and Compress.
The Velocity parameter is an offset value, so increasing this will play the notes harder.
The Compress limits the dynamic range in % so using these together might be a good idea.

/Robert