Freezing will be in renoise 2?)
No, but it will be in your freezer.
I think you should wait for the official press release about renoise 2.0 or 1.A or whatever. Or search the forums, there are some clues left around which is going to be added and which is not.
what, you want Renoise to become unstable??? 
Why should we want freezing if we can just 'render selection ’ ?
I mean there is no added value , rendering selection is so flexible !
yes indeed!
I think audio track support should come first.