I downloaded three archives (bin 68040, datas and doocs) and tried to install. Everything went fine though I had the same error on every three installations: "OPENWBOBJECT - unknown command". Well, not a real problem since I've checked installation script and that command is at the very end of installation. So nothing is missing after this stop.
I started unarchiving binaries and once finished I deleted files and archive. I did the same for data archive but without unarchiving, since inside lha file there is another lha file with the same name. MorphOS can open this kind of file so I've opened archive, selected all files and moved in the ram disk and then installed. After this step you will see all the proper icons. Last step unarchived docs and installed. Done! Started without issues it works fine. But you couldn't use it for your sound edit because this is a demo version and you won't be able to save your work unless you have your key file. Well, Sound FX worths the 20 euros it costs for what he offers!