1- Not sure. Check this:
http://www.thestudentroom.co.uk/showthread.php?t=5620422- Weighted GPAs allow for classes to count for an extra gradepoint. For example, an AP class often counts as a weighted class. Usually, on a 4.0 scale, an A counts as a 4, a B as a 3, a C as a 2, and a D as a 1. Weighted classes are one gradepoint higher (A counts as a 5, B as a 4, etc) and raise your GPA. A weighted GPA allows classes designated as weighted to count for more points and therefore your weighted GPA is higher than your unweighted GPA. An unweighted GPA treats all classes as unweighted clases (aka A=4, B=3) and a weighter GPA allows for some weighted classes (A=5).
Example: you got an A, a B, and a C as your final grades. The class you got an A in was a weighted class like AP English. Your unweighted GPA would be 4+3+2 divided by 3 = 3.00. Your weighted GPA would be 5+3+2 divided by 3 = 3.33.
Hope that helped
3- I guess international.
Where did you giver yer exam from?
4- Maybe we aren't used to their system probably.
All I know is that MOST universities in US require SAT I & II (sometimes).
Check yer desired uni and their requirements. (: