Hello,
how about a tool that could FINETUNE all the samples located on a track by a percentage?
That would remove the any need for additional enhancements on the sample editor - because now when you compare renoise to any other software the thing lacking is that you cannot tune your clips altogether.
erm… sorry but I don’t see how that can be used to tune multiple samples altogether?
Why would fine tuning samples negate a beatslicer?
It would not negate a slicer - it would replace the need for it…
If the finetuning of multiple clips would be possible, you could do everything inside Renoise that you commonly do when using a beatslicer. If anyone finds any other feature that Beatslicers commonly have and Renoise doesn’t - please feel free to post them here 
Automatic groove quantizing.
… which btw, would be great with automatic hit detection (another thing renoise doesn’t have) … because you could use it on things like natural atmosphere sounds (like rain) and make rhythm out of them. You could also use these two features to correct the timing of vocal tracks and such.