You are feeling the same pain points as I am. To me the graph window is almost unusable — if I need exact values I just jump to the key frame then adjust the value as needed. That being said, graph window improvements is on the list.
pI3 had a “Replace Emitter” function, and we’re planning on adding it in PI, but it’s not there yet. I know your thought process because you looked for the next best thing: copy and paste of keyframes or something similar. Sadly that’s not possible yet either.
Be patient, we’re getting to all of this. There are so many details to implement, while adding new things too. If you want to get on the beta test for PI and the rest of BCC, send me an email.