1. Absolutely yes. You can't stop in a short enough distance with an extra 3-5,000 lbs pushing you.
2. Trailer towing wiring has almost nothing to do with how the lights are set up for toad towing. So no, you can't plug into the trailer towing harness.
Roger & Mary
2014 Tiffin Phaeton 36GH
2012 Honda Fit toad