You said 25 amp run, and no way are you going to pull that. Most cigarette lighter sockets are only good for 20 amps, using a lighter, less with a plug in charger, more like 10 or so. The usb is only good for 1 amp or less, very small wires. I don't advocate running a small wire, but don't get too big either, especially the price of copper wire.
While you are looking at the schematic, the physical doesn't have to match. Run a 12 gauge down the center of the trailer, to a point, turn it for the dedicated 12 volt outlet. At the turn, tap it for the other outlet and USB port with a 14 gauge. Put a 20 amp fuse at the battery, for the whole ting. Fuse the USB with about 1~2 amp, and you're good to go.
2012 Ford F250 ext. Cab 4x4
2002 Jeep Wrangler Sahara
2008 Yamaha V-Star 650 Classic
2008 Work and Play 18LT