Just let you know my previous experiment.

I did screw up my S2 last time with custom ROM and cant recovery, end up i send to Samsung Service Center for recovery without revert back to stock ROM & reset the counter.

No charge from SSC   

So dont worry too much

Actuly AP warranty dont care you phone root or not .

Its nothing about they care or not. They can use it as a reason to void your warranty.

SME void your warranty because 1st its their policy 2nd its their name

AP company void your warranty so they do not need to bare the repair charges. They take back from oversea lets say RM1k sell to you RM1.5 k you root it then they find out you rooted it the LED display could cost RM900.

I think they will choose to void your warranty if they want.
But SME they cant if you complaint to tribunal or newspaper their SAMSUNG name get affected.

AP company their shop close down and thats it is AH KAO SDN BHD affected only

If you want to go some serious Android-ing, XDA forum can really teach you many stuffs 

iphone does not have international warranty. ipods, ipad, macs yes

You can always write to Apple officially to confirm
I remember reading it in their terms of sale no international warranty for iphones ONLY

PERSONAL REQUEST : Please STOP PM me all questions about Note 2. My inbox is getting full. And every day I clean it ,. it gets fill up within next few days
Please post all your queries in this thread. There are more knowledgeable users than me. I am still learning stuffs every day. MY answers might not be totally correct. You post in this thread you can get faster and even better response. If you guys PM me and I dont answer I feel bad. Worse repeated questions I get even more pissed off reading it. Such questions you can easily use SEARCH TOPIC in the thread to find the answers
I just recieved a very long PM about 50 sentences long and just reading it just kill my interest to answer it when all his questions are common