I don't think you can force the panel behavior on it's parent, it's supposed to work the other way round. And because I don't think you can change the alpha of Bartender Bars between more than two values, like say 0% and 100% you either have to be satisfied with those two or maybe take a look at
this.
Not sure if you can do it that way because I never used more than 2 alpha values. If it does work with more than two alpha values you only need to get the macro conditions and it should be a solution to all your other requests.
I might be wrong with the panel-parent behavior but I'm fairly certain I remember it correctly.