I really love Renoise Sample editor. In past few months I am using it daily for clearing vocals for videos, cartoons and composed songs and before I add compressor on whole sample track / song, I create all peaks to be nearly the same height.
To make “non-clickable” volumes, I enable “snap” icon and then select sample, part by part and each time I raise or lower volume by hitting “F10” key which will bring me “Adjust Volume” window where I either RAISE or LOWER sample selection for + or - 0,500 or 1 dB.
I’ve also configured CTRL + SPACE to “Silence Selection” (much faster than previously: hit F10, set volume to -INF dB and hit enter for process) 
I have question:
1 - Is there easier way to adjust volume for default 1 dB without need to hit and oper F10 window? It would be fantastic if there will be buttons to + or - sample selection directly in Sample editor. Maybe it would be possible to create (and add short-cut key) macro or script that would speed up working with samples a lot?
2 - I have one more question: when I zoom sample (with middle mouse button wheel), would it be possible to set “middle mouse button” key to act as “hand tool” (or “Alt” + “Middle Mouse Button” for scrolling zoomed sample left/right? The only way (that I know) is - zoom sample and watch it left/right by holding “LEFT ALT” and “mouse wheel”?
3 - Is there possibility to enable helping “guide lines” in background of the Sample instead pure black background, as seen, for example, in old WaveLab software. Those guide lines are 50% below and 50% above sample’s central line (which represents “0” / Zero. Above is +100%, below is -100%. Guide lines are on 50% and would help a lot for clearing and fixing samples volumes - matching guide lines height, for example.
4 - And finally - Are there possibility to open “Modulation” tab OVER “Waveform” tab so we can easily make for example - volumes on samples (that would be non-destructive), as seen in WaveLab or Adobe Premiere (where you can see wave below video in time-line where you can add volume, reverb, compressor and many other basic effects)? If yes - how?
Modulation tab is not very useful as you work on “what you hear” instead - “what you see” (as expected), for more precise work. I guess - there is some “hidden” button to show sample in the background of “Modulation” tab
Cheers!