In my 1991 525i auto it can. The ignition turns off and the steering will lock if turned. Bad idea.
Nothing. It will keep on driving. There is a safety on the gear that will not enable it to be activated while in movement. It may destroy your gear though.
the transmission will shift to higher gear
Bang depending on the vehicle, you will ruin the transmission.
It goes into reverse gear, nothing else.
no the gear stays in place , unless you take the timing gear cover off + the bolts that hold it to the cam shaft.no it won't change the position either unless you crank the engine, the gear stays in place.
there is no forth gear
I pulled your moms throttle into fourth gear.
80/90 gear lube
if you are missing any gears in your manual transmission it is shot. You might as well replace the clutch while you have the tranny pulled so you dont have to do it later.
Gear up then
You can renew it by pressing the gear.
the smaller gear makes the bigger gear a unicorn