Best way to manage well-defined actor functionality consisting of multiple components?

[Countsie]

@JoSf

But Unreal does not let components have subcomponents or actors add other actors as components.

Not true, friend:
AttachActorToActor
AttachActorToComponent
AttachComponentToComponent… etc

If you are creating them runtime, assign the reference to a variable then manipulate it there.

Composing an actor with component functionality as you outline is what UE5 is pushing as best practice. You echo exactly their thinking on the limitations of inheritance… just dig a bit harder and you are right there.