Hi Richard,
In regards to your question about depth, the depth knob will produce only the phase shifted signal when the knob is at 0%; this is why you hear the woozy effect. As the depth goes higher, the amount of dry signal is increased with 50/50 wet/dry at 100% depth. This is because of the way that the phaser/flanger sound is created. In order to have a completely dry signal, you are correct in automating the power on/off. I have been unable to reproduce any problems with this on my end; can you confirm you are using the latest version of the plug-in, as well as let me know what operating system and DAW you are using?
-Quin