Is it complusory to apply for FSW category from your home country while you are not in home country, does someone can apply from other (UK/USA) country while he is on study permit in that country (UK/USA). if so, then initial application you will be send to CIO, Canada. what about the complete application, where would you send it. would you send it to the respective (UK/USA) country's CHC or to the home country's CHC.
You don't have to apply from your home country. If you are on a study or work visa in another country and this is a visa for a year or more, you can ask for your processing to be done in that country. To find out where to send your application, read the application guide. I believe they are all going to Sydney NS now.