Always so dramatic. You do realize that none of the Shift + AltGr values have been set in stone yet(or if they'll even exist beyond the uppercase umlauts)? You also haven't given me a list of these supposedly crucial Shift + F-keys you're desperately and repetitively in favor of not losing. Care to share them, or will you sidestep the question yet again? ^_^
Who said anything about crucial and desperation? I'm just saying it should be possible to do Shift + F-keys, like it should be possible to do Shift+space, Shift+enter, Shift+backspace and so on. If you want some Shift + F-key shortcuts to understand the point, I'll give you some:
In the text editor I'm using (MCEdit), "Save" is F2 while "Save as" is Shift-F2; "Search" is F7 and "Search again" is Shift-F7.
In the browser I'm using (Firefox), you can go navigate between frames with F6 (next) and Shift-F6 (previous), when searching for something (Ctrl-F or F3), you can use F3 to find the next occurrence and Shift-F3 for the previous one. Shift-F2 shows the dev toolbar, Shift-F5 shows the profiler, Shift-F7 the style editor, Shift-F4 the scratchpad.
In the word processor I'm using (LibreOffice), the default shortcuts include Shift-F3, Shift-F4, Shift-F5, Shift-F8, Shift-F9, Shift-F11, Shift-F12, Ctrl-Shift-F5, Ctrl-Shift-F8, Ctrl-Shift-F9, Ctrl-Shift-F11, Ctrl-Shift-F12.
Obviously there are alternative ways to do those things. You can use the menus, for example. Or e.g. in LibreOffice, you can easily modify the shortcuts. But that's not the point. The point is: why make things complicated and make Shift + F-keys do weird stuff?
WiFi and Bluetooth are regularly used toggles, and while your "wonky" hardware key does save space for Escape, Insert, and Delete positioned way up top(also to be accidently pressed as you've worried), it will require someone to code a gui popup to show present status for it with absolutely zero guarantees it won't clash with other opened software the individual may find themselves using at the time, if they want to render WiFi, Bluetooth, or the like active.
I think such a popup / on-screen-display / menu / notification thing has to be coded anyway (or perhaps / probably something like that already exists). Or do you want your toggle buttons to do their thing without any visual feedback? Do you want the power button to immediately shut down the device, without any confirmation dialog?