Well I would change the clip names of this stuff in my Event Browser to “Drums” “FX” ‘guitar” etc. I would try and use Smart Collections where possible also to keep them all nicely bundled together.
So I would immediately see what they were in my timeline. We can differentiate between “audio and video” and just “audio” in the timeline at a glance can we not?
And of course I would also use roles to make sure FCPX “knew” what everything was.
Sync markers we are missing. If you detach audio as opposed to expand that is potentially a bit of a faff because you have to match frame (sorry reveal in event browser ) to sort it out but I have not found that to be a problem such is the beauty of expand audio
Am I being obtuse?