I'm kind of happy with that solution. However, if the SystemTags() is used with the ASYNCH flag enabled, it doesn't return -1 when the command can't be found (i.e. trying to run Mlutiveiw, and not Multiview, return 0 for success), so one can never tell if the command could be started or if the exit code is from the Shell trying to start it. This can perhaps be solved by starting a process that calls SystemTags, with ASYNCH disabled. But I still have to find out a way to know if the SystemTags() succedded... probably by some intrinsic use of wait:s and delay:s... which is not very safe without Forbid() and Permit().
Also, trying with mauve fails. There seems to be something about mauve that likes to create new processes, causing memory failure, which will lead to JAmiga crashing.
Moving to more fun stuff, I tried the AWT classes, which can probably relatively easy be made to work again -- Intuition stuff work, and it seems to be a mere configuration issue initially.
The JAmiga project is continuing...