1. It's true that you're tracking an external signal directly in LOC, but you can't select a different value. For example, you can select speed 250 and adjust it, you can select a heading/track and adjust it, but with localizer you can only capture it. Additionally, LOC* mode includes "Enhanced LOC capture function", which uses FM position in order to make anticipate LOC capture and makes a smoother turn to the localizer. So it's not just external data.
2. Nothing wrong, the APU bleed air valve won't open until APU N > 95% anyway, just not the way this things are done.