I thought that polling could cause things to slow down so maybe thats part of it. Old GE switches were notoriously bad at least according to these forums
As far as things included but unplugged - that doesn't appear to be a good idea but I dunno if it is okay within the bounds of the ZWave spec. I guess the network will eventually sort itself out but turning "routing capable devices" on and off seems like it may cause chaos at least temporarily.
