The Rig/Talker issue was one that got a lot of thought when we first designed Rigs. The first thing to remember is that Rigs are designed to become pluggable and in fact we are not terribly far from this being a reality (as in a few days work according to Jim). This is a very nice feature to aim for, but has a few difficult implications, the most difficult of which is how to make Talkers play nicely in a more dynamic environment.
We considered two different approaches. The first was to have some kind of 'action' connection on the Rig boundary and route talker connections through these intermediates. The second was to allow Talkers to be re-evaluated when the contents of a Rig are changed. Quite a bit of discussion when around these two approaches but it eventually became obvious that to keep the power of Talkers, which is largely there due to their apparent orthogonality to the connection system, we'd have to implement the second option. For a number of reasons that implementation is difficult. Not impossible, just hard - it involves implementing a reliable dependency management system for Talkers as a first step (ie, knowing what a given Talker action object depends upon) then making the re-evaulation of the Talkers that get tagged as invalid after an internal Rig change a sane process, ie; one that doesn't glitch your processing for ten minutes while it happens.
As you have discovered, this has not yet been done. An initial first step will be to simply re-evaluate all Talkers when a rig is changed. Perhaps the best approach will be to make this a manual thing, so that the large CPU crunch it will cause is not a surprise. I'm sure there's probably a middle ground before we need full dependency management. I think that after we have the Conductor running, getting Rigs to be pluggable with functional Talkers has to be near the top of the development wish list. If anyone want's to have a look at this issue who knows their way around EigenD internals then please talk to me and I'll see if I can get you some help.
I agree we should probably have disabled making Talkers in Rigs somehow for the meantime, but the work that could go into that logic could also go into something else and the priority was spent elsewhere. And things like that that sound simple nearly always end up as giant time sinks, it seems to be a rule of the software universe.
John