Help with Daily Driver? Please?

I am guessing;
Is it possible that 1) the ignition system is cutting in and out? or 2) possibly that the vehicle is losing all electrical power?
Either of these would cause the brake-check feeling as the engine goes into engine-braking; But
1) the loss of ignition would cause only the Cel to come on. whereas in
2) as soon as the power is restored, the ECU would do a self check, same as it does when you first start it. and ALL the lights would come on.. momentarily then all would wink out.

As for #1, I think a failing coil would do the same, if the '07 still has the single E-core coil. However, sometimes what seems to be a failing coil is actually a failing signal to the coil, which would then point to a failing Crank-position sensor, or a bad circuit in the computer, or a bad power-supply to it.

As to the high rpm at 70, that would be the overdrive and lock-up kicking out, which could be for the same reason, namely; the computer lost signal, and has to re-establish it's parameters.

I am guessing.