I propose three new buttan/tools in sample editor.

1. Live amplitude editor.
   Enable mode to add envelopes in the sample editor, by points. Same semantics as instruments, except tied to middle axis(amp or decrease vol).
   These update waveform live so you can see what you are doing. Optionally, affect playback live.
   When you are done, can discard or apply to sample.
   Use: fiddle with sample dynamics.

2. Live DC offset editor.
   Similar to above in operation.
   Use: correct wobbly DC offset before fiddling with dynamics, impromptu half-sample distortion!

3. Loop overlay mode.
   When mode activated, if you are looking at loop start/end, view overlayed waveform with different color.
   This is less pressing with technological advancements such as crossfading, but personally, I'd rather butcher as little as possible.
   Caveat: cannot see properly if at the very start/end of sample.
   For this I propose: split view. Draw another sample view in line with the real sample view, but dedicated to loop viewing, own zoom, only activates with mode.