If you have recorded at too high or low a volume for the faders to be effective enough, you should also be able to use the input gain of each channel in your DAW to lower or raise the pre-fader volume.
You should be able to select the algorithm used for time stretching (might depend on your Cubase version), e.g. Elastique Pro or soloist, etc. I think you'll get varying results depending on the source sound being stretched.
It's data. It represents voltages that move the speaker cone. You could interpret the data in any other way and display it as text or colours, depending what you decide the depth of the groove (and the associated numerical value) means.
You could do a lot worse than the Vox AC15HW1X. Those things do glorious, sparkling cleans at reasonable volumes.
Vox AC15HW1X Hand-Wired (Celestion Alnico Blue Speaker)