STPM is recognized in the US as an A-level equivalent, and might even be regarded with most prestige due to its difficult nature.

You will need to take the SAT REGARDLESS of whether you take STPM or A levels or IB, but you may choose to take the SAT on different dates, as long as it is not before January (December for some, most universities will have application deadlines on New year)

Source: Malaysian studying in the US.

You will need to take both SAT and STPM if you wanna go to IVY league or other university in US or around the globe.

Well I scored four flat in stpm last year and have accepted by NUS and NTU in sg as well as unis in UK. It is quite easy to got accepted by NTU as long as you can score 3.92.  For the co-curriculum part, you should choose wisely, join those clubs or activities or competitions at international or national level and try to avoid some activities at school level only, unless you feel that it wont affect your study and you really enjoy it then go ahead  As now stpm has changed to new modular system in which you have to sit for the real exam for about every five months (deduct holidays), there will not have sufficient time for you to active in school co-curricular activities, well I couldn't make it, if you think you are capable then no problem 

Doing that might set you back by a year since the deadline for universities is usually on Jan 1? Which means you will only get to submit your application on Jan 1 2017 and enter in Fall 2017. Unless you don't mind it.

Yes. The deadline for each batch is January 1.  So if you take it in May/ June 2016, you would have missed it already and have to wait to apply at the end of that year (which closes on Jan 1 2017).  Which means you would be admitted in Fall 2017. Try to take your SAT in May/ June 2015 and apply just at the end of your Upper Six. You don't need your actual STPM results. Another thing is that you cannot take SAT I and II on the same exam date. So you need to keep two dates available.

Hi, after stpm when ur result come out u can try to apply for the oversea uni, it is possible u will be accepted.

You also can participate in extra cocuriculum activities and u should participate in cocuriculum activities because it will help u get the higher cocuriculum mark.

Nope. Lol. I'm still in Upper Six. You can also take SAT in Oct/ Nov/ Dis (not very sure) so maybe take one during mid-year and one at the end of the year? Yea, it sort of clashes with our semester exams. Have you heard about USApps? They do workshops so see if you can go to one.

It's really need study hard is true, but not so horrible like u have to study like crazy people, you will have ur form six life.

Ya, it is depends, u will not regret after u study form six.  

Remember every topic that teacher teach at school after go back home need rereading or u can do ur own note, it will make u more easy when u want to exam.