04 Envoy won't go into reverse. When put in reverse just sits there. When put into neutral starts to roll forward as if in gear. It drives in neutral as well as the other gears.

Try stepping on the brake when trying to shift with the key on. Then try starting im neutral or other gears to see if the neutral safety switch is bad in park. You may have a bad wire from the battery to power distrubution or bad ground. So many things it could be.

If you put it in neutral with the engine not running and have someone push it what happens?

The question is a little vague but I think I know what your referring to. All modern automatic transmissions have torque converters. This is the device that connects the engine to the transmission. All vehicle manufacturers like the trans to be nice and smooth shifting. That's great but it does come with some minor drawbacks. If you are facing slightly down hill and you put your car in reverse but do not step on the gas slightly I can guarantee that you will indeed roll forward. You can eliminate that issue by holding your left foot on the brake while you shift into reverse. Then, as soon as you feel the trans engage, gently depress the gas pedal with your right foot and it will eliminate that forward roll problem.

Your transmission needs to be repaired. This is going to be at a starting point of 1700.00 and cap off at about 2300.00.

If it is like other cars with automatics, the neutral safety switch won't allow starting in gear. The park/neutral switch would not allow current to pass through to the starter motor from the ignition switch if it is not in park or neutral. This is a safety feature, and probably universal.
Pull one of the spark plug wires from a spark plug and check for spark while the engine is cranking over. If no spark, the ignition system needs diagnosing. I have no idea where to go from there on a Rolls Royce- it would be rather primitive compared to modern electronics, but then on a rolls, well you get my drift.

Sounds like an internal problem.

https://www.youtube.com/watch?v=Bce2OAA8Hyw

Sounds like a cable to the transmission is not adjusted up right, and/or the neutral safety switch is not adjusted right, if this applies to your Toyota Corolla.

Sounds like the cable has shifted, from the gear lever to the transmission there is a cable that puts the transmission in the correct gear. this cable is adjustable where it bolts onto the transmission and has probably moved

shift linkage needs adjusting,,could be bent, easy fix, located along firewall to fram beneath the column, ask your son wut he ran over and didnt tell u about... hope i could help...:)