Great modification in the name of safety. There is one small change I would recommend if your parts allow it. You put the male plug in the fuselage, leaving two long connectors exposed which could potentially short and power the ESC if something conductive touched them or got stuck in the receptacle. (zipper pull, key ring, lanyard clip, loose wire, paper clip, who knows.)
The possibility is slim because the male plugs are recessed into the receptacle, but it would be safer to put the female side of the plug in the fuselage and have the male plug into them. Just a thought. Enjoy!
You're absolutely correct, it could happen. There were no instructions with it (big surprise from Hobby King on that) so I tried it both ways and it *COULD* work with the plug reversed, but it was difficult to get the removable plug installed. It would have to fit evenly between the black housing and the yellow plug and the pieces shift a bit when pushed. It's hard to explain, but it's far easier to plug it in this way. Some epoxy would probably help hold things together if the XT60 connections were flipped around, but then it wouldn't be removable or serviceable. Overall I'm not too worried, the chances are slim that something metal will hit the contacts while a battery is installed.