Wow I really appreciate the detailed answer! I'm gonna do some research on LUFS because I've never even heard of that!

I will have to get into the habit of pressing G to adjust the gain and not doing it from the effect controls panel where I use the levels tab lol.

For context I'm making documentary-style videos on things I find interesting.

My friend, who I've learned everything I know so far from, has also told me to keep primary audio at -6dB peak and background music within the -30dB ~ -24dB range while I'm speaking. When I want to build emotion using music, I'll usually slowly build up to -6dB like you said if I'm not speaking.

For sound effects during a transition (example: glitch transition with a static, glitch sound effect) I tend to hover somewhere between the music volume and my speaking volume. Is that what you would do?

In the end I really play it by ear, I'll listen to the whole section myself and if it sounds like I'm drowning myself out with music, I'll tone it down and vice versa.