I would like to answer your questions 2 & 4
2) Use D for normal Driving. S stands for "Sports" mode, it is used for faster acceleration, it limits the car's computer to select lower gears, hence quicker acceleration. This is used for upward steep slopes, or for fun, or racing etc. Obviously your car will consume more fuel if you select S. Therefore, try to use "D" as much as possible, to get better fuel economy. Even for the regular slopes you see in Pakistani cities D is fine, unless you are going up on steep hilly roads like Murree etc.
B stands for Brake (or more precisely "engine Braking"). If you select B, it improves braking of the car, particularly when you are coming down on a downward slope/hilly area.
4) Your car's gear pattern indicate that you are having a CVT gear system. And for this gear system use only Toyota's CVT-TC gear oil. NEVER EVER use regular AT oil.
Hope it helps.