Your best approach would be to do multiple rips at various quality/bitrate levels and judge for yourself.
Just rip one short chapter/segment.
My main Handbrake usage is to transcode 4K source to 1080p for playback on mobile devices, my Raspberry Pi 4 running Kodi, etc.
I set output framerate same as source framerate, 10-bit HEVC encoding (CPU based), audio passthrough and a file format that is compatible with iOS devices. For 1080p output, I find that 8000 kbps bitrate is a good compromise between file size and quality. I usually do a two-pass encode (Turbo first pass).
For 480p output, I generally stay around the 2500 kbps bitrate range, especially if the source material is interlaced.
For audio, a lot of it depends on the playback device's capabilities. I've discovered that my RPi4 running Kodi can handle more audio formats than my five-year-old iPad mini (4th generation).
Also, that iPad mini does not like some high-bitrate HEVCs. That's fine, I'm due to replace it someday with hopefully a 6th generation iPad mini. I have enjoyed a LOT of use from my iPad mini. I could encode everything to H.264 but I'd rather give up a few files on the iPad mini than use an older encoding standard.
Curiously, I can copy the "incompatible" HEVCs to the iPad mini's VLC app where they will play fine.