Thanks for your answers.
With regard to 'jumps':
I was thinking about have a set of memories that would be used repeatedly. If there was a 'return', then you could treat it as a callable unit (eg. cue 3 - jump to 100, do some stuff, return (to 4), do some more stuff, cue 32 - jump to 100, do some stuff, return (this time to 33)). Make sense ??
Long fades and interference:
I can see how the submaster solution would work in my example, but what about the case where you are doing a long fade (whole scene for example), and want to process a number of cues on the way (being an amateur group, the operators are not always going to be experts!). We just want to be able to hit 'Go'. It would be solved if a channel could be marked as "not active" in this memory, and any current changes to it continue unchanged (ie. the long fade still progresses on the other channels). This does mean that at any point in time you could have several fades at different rates on different channels. Its a feature we are used to (hence the question). When programming the memory, you could use the flash buttons, say, to mark active/inactive channels.
Do you release the file format of the saved show files. That way I could write my own offline editor?