In your proposal the opportunity cost associated with a bond is a further deterrent to setting up multiple nodes. In the current system design, the bond will indeed earn delegation rewards. Anything bonded for P-RepA will also be delegated to P-RepA and therefore earn rewards.
Personally I think that in this situation the cost outweighs the benefit, but if you feel strongly we can vote specifically on the topic of whether or not a bond should be able to be delegated.
As for the concept of capacity, that’s already how it is designed, so no need for any extra work or development on that topic unless I am misunderstanding you. We have the concept of “bonded delegation”. Let me know if you are unfamiliar, it was explained in the IISS 3.0 thread