I was driving down the highway and the transmission just quit, I coasted to a stop and have no reverse or drive. Can anyone help?

oil out of the breather is an indictation of excessive oil
if it drives as would be expected, there is nothing wrong with the transmission so move away from the mechaic who stated that ir was "fried"
at 60 mph the rpms should be in the vicinity of 3000-3200 rpms and go up about 250 rpms for every 10mph over that
have the fault codes read or take it to an accredited transmission professional shop and have the bands and clutches adjusted

When is last time you changed trans fluid and filter?

Drive it slowly to a reputable transmission shop. There is nothing you can fix yourself.

Time for a rebuild

it sounds like you have to much trany fluid in the trany.check the fluid level .if fluid is to much it bubbles at high speeds and if to low it can slip

I would solve the electrical issues, before I would let anyone
pull the transaxle out

A trans shop is not the place to be for that

I used to own one

They will rebuild the trans & you will still have
the other problems & they won't have anyone
that can help

Choose 2nd that way the car will not coast to fast and it will also slow it down when your stopping but if its ice throw it into reverse so it will help stop

you need your transmission rebuilt the clutches are slipping

GO WITH THE CHEAP FIX FIRST CHANGE THE INPUT , OUTPUT SOLENOID AT ONLY $30 A PIECE AT YOU LOCAL AUTOPART IF IT DOESNT WORK CHANGE THE SOLENOID PACK , AT $ 125 AT YOUR LOCAL AUTIPART
LAST FIX IS THE COMPUTER LOCATED UNDER THE SPLASH GUARD AT THE DRIVER FRONT WEEL
YOU CAN GET IT REBUILD FOR $150 BUCKS

First off, I'd try changing the fluid and filter in the transmission. I know a lot of cars claim "lifetime fluid" - it's BS. Believe me, even the lifetime fluids get very dirty. Change out the fluid and filter, and you could even add some Lucas stabilizer to it - that may well help cure the problems.

When the transmission goes completely, it may lock up the drive wheels, sending you into a careening slide, or it may kick out to neutral and coast to a stop. It's also possible that if it flat-out blows, it could fragment inside and you'd hear what sounds like bolts in a blender as you coast to a standstill.

Discounting the transmission blowing up, and just looking at driving in a drive gear other than overdrive, you're looking at more heat in the transmission due to the higher gear RPM, shorter fluid life, possible slippage of the bands down the road due to heat, and of course decreased gas mileage due to the engine running at higher RPM.