In case you didn't know: You can install a squeak vm via easyDebian. A new v4 virtual machine is available in the testing repository. Then I just grabbed the v4 platform independent files (image, sources and changes) and the thing started without complaints.

I have not yet done any serious programming and I didn't check sound and network.

Performance is okay, a bit sluggish but usable. The extra buttons of a three-button mouse can be emulated with Alt or Ctrl. The v4 GUI looks a lot more polished than the v3 did.