Why Component Editor designed so horribly (half-baked)?

Hi, guys, I need to make an actor made of many parts.
From what I researched, having many Actors can affect performance, thus making the parts as SceneComponent makes better sense.

So far so good. The part can have self-contained animations and effects that need to be composed of several Components.

Here is the first surprise.
Component Editor doesn’t have a Viewport. I can’t see anything while making the Component. Yeah sure, There is ActorComponent that can’t have visible elements. But anything other than ActorComponent can have visible elements. If we are editing none other than ActorComponent, it makes sense to have Viewport, no? There doesn’t seem like any good reason why Viewport is not there. Please don’t tell me it’s because ActorComponent can’t have visible elements and it’s removed altogether.

And here is the second surprise.
You can’t add Child Components in the Editor. Components clearly can have child Components but it’s only doable programmatically. Why??? Without being able to add more than one Component, we cannot make a sophisticated Component at design time. This is quite a big limitation without a good reason, again. Yeah, sure Component is not the same as Actor but from designing point-of-view, we should be able to add Components, no?

My impression of Component is that it is a very powerful tool but working with Component is very difficult. The limitation seems arbitrary and with little care, it can be much easier to work with.

Epic, please support Viewport (for PrimitiveComponent and its derived Components) and the ability to add Components to the Component Editor, or please explain why such limitation must exist. Not being able to understand the limitation is frustrating. If I understand why the limitation must exist, I think I must use Actor instead of Components but it will affect the development quite a bit. Thus, I had to ask first.