The Pre- and Post- fader issue doesn't affect the OP's original issue, but is almost certainly what you need to address. If you apply effects Pre-fader then the effects signals you get when you push the fader up and down will alter with the fader level. If you put effects Post-fader, then the effect level will remain the same whatever you do with the fader.
As for the rest of it, it's relatively simple to explain, but it does require you to understand what a hardware mixer does, because that i
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