EDIT: Make that one suggestion. I just found out that you can already do what I asked for in the second one.
Image-line has an awesome audio manipulation tool called Edison (and it’s close cousin Slicex, for slicing, obviously). They both support writing markers to Wav files and reading them. I’ve now discovered that Wavosaur can also write its markers to a Wav file, and that both Edison and Slicex can read them. Reverse is also possible. So, I imagine there must be a standard way to embed markers into Wav files. Sadly, Renoise doesn’t support this. It would be awesome, though. I sometimes whip up Wavosaur to do some slicing, because doing this in Renoise isn’t very comfortable (yet). There are also some Wav files that I’ve sliced in Slicex that already have markers, and it would be nice if I could load them.
Another suggestion is the way selection works. I’m sure it’s been mentioned here, but since I couldn’t find it, I’ll risk adding a duplicate. If I make a selection in the sample editor, then zoom out, there is no way to modify the selection. Wherever a click, the selection will go away. What I would like is either that edges of selection can be moved by dragging, or that clicking anywhere outside the selection extends it (or shrinks it if I drag towards the other end of the selection). Former method is the way Wavosaur works, and it’s pretty intuitive. Latter method is the way Image-Line’s Edison works, and it’s quite counter-intuitive at first, but very efficient after a while.