I'll chime in on the wiring...
It's a lot easier to do this:
1. Use a Xacto or a razor to cut away the USB wire molding. I just made incisions and pinched it off with a needle nose pliers.
2. Once you cut the molding away you might have considerable amount of silicone as well if you are using a nice one. you'll need to make incision and pinch them off too.
3. Shorting out pins on the connectors is VERY hard. mainly because the contacts have to be heated in order to make a solid link BUT the plastic holding the pins will melt trying to do this.
4. Take a look at the Back of the Micro USB cable, there are 5 contact points, only 4 are connected, and 1 should be empty. you Link the empty one to the black one using a nice clean copper wire.
5. The Top portion of this picture shows best. 4 Would be blank, 5 would always be black. so put some solder on 4 to prep and run a wire from 4 to 5.
6. You are done! becareful not to touch other solder joints creating others contacts to short out, Only 4 and 5 should touch. I've used my multi meter to make sure all was connected and ringing properly.
Good luck. not too challenging if you "do it from behind" lol