The yellow wire nuts on the brake wires seem to be the standard method of connections.
I would always check mine when on a long trip as they did come apart on one of my trilers once. I would think a butt crimp would be more secure, but if they have held for this long who am I to argue???
I do not know if the breakaway only engages the rear set of brakes on your model year, but let us know how the compass test works out.
Prior to rewiring the breakaway switch in I would test it with a meter to be sure it is functional. The fact that it is disconnected may be due to it not working, or working when it is not supposed to!