Newell Gurus

Your first question "Do the trailer brakes rally add to overall braking power?" Is yes they can. There are several different types of trailer breaks with the most common for bumper pull trailers being electric, but there is also electric over hydraulic, air, etc. Most of my experience is with the electric type. Normally with them you can set the braking force with the brake controller. When set correctly they will greatly improve your stopping ability. Set wrong and your breaks won't grab much or the other extreme is the trailer breaks will lock up the wheels when applied and you'll ruin your trailer tires in short order.

Also be aware if you go the trailer route there are many manufacturers who will only put breaks on one axle of a tandem axle trailer. I strongly encourage you to make sure all trailer axles have breaks if you go the trailer route.