I know that CN's GP9RMs and possibly other small locomotives have remote control, which is used allot in yard operations here, making CN successful with it. Some switchers made today might be ordered with remote-control equipment, though I've never looked into the purchases. If CN decides dumping their current fleet of yard locomotives, I think that they will go with integrating remote control into its "new" fleets.
Mid-train helpers being part of distributed power are there to reduce slack action, I think, which would tear a coupler off of its frame and socket. The mid-train helpers run in unison with the head locomotive, so there is a signal being sent from the main locomotive to the others.
Remote control is simply controlling a train with a remote interface, making the yards that have such locomotives, radar-enforced in most of the cases, because there is no engineers to spot you. It's no wonder that CN puts those big "WARNING: remote-controlled locomotives" signs up!
I have to ride seven kilometers to get to my railfanning-spot... and other teens think they have it hard!