The REST API might be improved at some point, but right now we haven't planned on improving it. I might take a look at it once we get the RF 4.0 support released.
Currently the API doesn't support the requests you asked. Those could be nice additions.
The reason why I closed the ticket was that the API exists and the issue that was discussed last was fixed some time ago already without any new suggestions/ideas. You could open a new ticket with improvement suggestions to the REST API.