The way I currently do things is I go through a sample or an instrument and I load it, then I play it using the qwerty keyboard, and if I like the sound as it is I keep it and then I find other instruments/samples. It’s annoying having to go through tens or so instruments and samples, having to load each one first and then to play it. It would be very productive if I could just click on an instrument and be able to use the qwerty keyboard to “preview” it as it were. Then if I like it I can double click it and load it. Impulse Tracker had the capability to do this. It went a step further, you were able to load instruments right from other modules. It would be cool if XRNS files or whatever they’re called could be used as libraries of instruments to browse through and find and preview what we like and then load them into our songs. Please make this simple as everything else is. 
Thank you.
This is already built in! for quite a while too.
http://tutorials.renoise.com/wiki/Disk_Browser#File_Panel
it’s that speaker icon
As Renoise does not have direct from disk streaming for instruments it is going to have to load it somewhere before you can play it anyway! I don’t see what is so hard to load an instrument/sample to play around with it properly. You can skim through with the Prehear and then only actually load ones that you think you might want to use. Whether prehear should be enhanced in some way for multi-sample instruments would be a valid question though…
I think some sort of a preview for instrument types would not be a bad idea. I think instead of giving it qwerty support maybe playing a C1, C2, C3, C4, C5 etc would be a good compromise between practicality and reality…
A while back I also suggested something similar to what Bojan is asking about being able to load instruments/samples from within another module… It was in a screen grab concept I suggested a while back about vertical scaling of UI elements. Basically it illustrated a tree browser, not a location/contents panel browser like we have now. An xrns would have a plus next to it allowing you to expand it to browse the samples/instruments contained within. I couldn’t agree more with addressing both of these suggestions.
Actually, I would like to see this feature too. Every tracker I used before Renoise worked this way – ScreamTracker 3, Impulse Tracker, MadTracker – and if I have to load the sample to hear it at different pitches/octaves, it’s immensely tedious to go through hundreds of different samples in different libraries, many recorded at different octaves, looking for just the right one. It’s also nice to be able to preview how a sample sounds in a chord.
As for your comment about having to load it somewhere – it’s already loading it to preview it, isn’t it? Is it really so much of a stretch to be able to preview at different pitches?
I bought Renoise today on an impulse, before remembering that this very issue is the reason I didn’t buy Renoise years ago. 
(Edit: OK, I must be smoking crack, MadTracker didn’t work like that either. And to tell the truth, it’s been so long since I used ST3 that I really don’t remember how it worked. I’d still like to be able to preview at different pitches, though.)
+1
An improvement of the preview would be great.
In particular for instruments.
Atm, using mouse: I click |>, then I click some .flac inside the instrument, then I get additional 500 ms latency, and then I hear it
My wish : I click the instrument name, no additional latency, and it plays instantly some defined stuff like C-4, G-4, C-5 on the currently selected track
(i just see mSepsis suggested a predefined sequence too)
And bojan’s suggestion should be included too, switching unloaded instruments while playing them.
It all comes down to a from disk instrument streaming as kazakore said.
Actually, there is some sort streaming (status bar says it) when prehearing samples, can’t that be used?
Would streaming from disk be too slow for high notes?
Or some zip or flac initialization takes too long?