SetOwner needs to be called on the server, only one client can own an actor at a given time. So there is no way to allow multiple clients to be able to send RPCs through the same actors.
Normally, there wouldn’t be the issue of sending so many interactions through the player controller, because the normal approach is just to send the player’s input, or direct results of their input, and let the server handle the actual interactions.
I am not saying that the way you want to do it is wrong, I don’t have the experience to know. But for sure, it does not really fit the standard client-server approach that the engine seems to be set up for.