I don't know where you guys @ DTG get your info but, In your tutorials with single locomotives you use the engine brake not the train brake to stop it LOL. Why would you use the train brake if you have no train LOL. What you need is an American hostler to let you know the ins and outs of how the physics work on these beast. Good Luck.
Yes you use the independent brake when running light engine. Yes if Dovetail does not have a contact who actually uses and operates American locomotives they should get one. I may be able to help with that.