Well, you've got a Tiida so you notice the extra noise when you go over 120.
I've got a Patrol so I notice the fuel gauge needle rushing towards empty when I go over 120.
It also gets noisier, but I just assume that's why there's a volume control on the extremely low tech radio-cassette that substitutes for the CD changer that they fitted to your car.
Brake Shoes? How old is your Patrol?
All GU patrols have disk brakes I think. At least they will have disks at the front and possibly drums at the back.
Depends on the driving, if a lot of downhill then there may be a lot of braking involved so the brakes will get hot, Much less so in a manual because you can use effective engine braking to keep the speed down.
There is an international deadline - you should replace the tires when the tread is worn down to the tread wear indicator
If it looks like this then it needs to be changed
This is the absolute limit, in areas like the UAE summer temperatures mean that tires have a hard life. Better to change them before they are 3 years old. Blow outs at 120 KPH are not a lot of fun.
Have you cleaned out the air filter, it can have a large effect on performance?
I have a Patrol 4.8 that had no power, I learnt to tap out my air filter after every trip