Hi Ronnie,
Doing all the mods that you have suggested will make a big difference to the way the car handles.
As to your question regarding the whether the rear toe out mod will make a big difference....well it does make a difference but not a big one. I noticed that the rear end 'bobbled' about a bit less on bumpy roads but to be honest you can leave that mod until you've put some miles on the car, you can then decide whether you have a rear end issue or not. (Tyre wear will be worse without the mod).
Noel's car has all the mods apart from the rear tow done to it and he described the difference as "profound!!"
Make sure that the front toe is set to zero and that the rears are NOT used to set the fronts up. If the front toe is not right then all your effort will be wasted.
Regards,
Pete