You wish to know their fees, give them a call. They vary tremendously within Selangor and KL (some cost RM2000-RM3000 a term, some cost over triple that each term, some cost over tenfold per term).

8am to 6pm is really dramatic. Primary school kids don't usually attend school for longer hours than secondary school kids (unless it's one of those unnecessary things like extra hours before major exams). If they start at 8am, they should end at about 2-3pm, or earlier. Extracurricular activities are obviously not compulsory to the point where you'll have to stay back more than 3 hours every day - that is ridiculous. Do not forget we're talking about primary school.

Chinese classes would generally be optional, and of a relatively mediocre standard.

Syllabus varies. There are British, American, Australian, Japanese, French, and German schools/systems.

Most common would be the British system, where those in primary and secondary school follow an English-medium curriculum (loosely following British or Singaporean primary and lower-secondary school education), up until Year 10, where they start preparing for the major external exams at the end of 5th Form or Year 11 (namely IGCSEs from Cambridge or Edexcel, and/or the fading GCE O Levels from either board).

Following 5th Form, students either proceed to 6th Form or the pursuit of an alternative Pre-University qualification (GCE A Levels, IB etc) at the same school or a specialised "6th Form college".

I know I might have gone on about what happens after primary school but it's good to understand the bigger picture. As far as I know what you do in primary school is of the least consequence as long as one enjoys himself/herself.