First of all, welcome to Canada.
Second, most of your questions have already been covered but a few addendums: because of the kind of grey-legal status of airsoft in Canada we're a tight-nit bunch and self-police ourselves quite well. You won't find many assholes as a result. The same grey-legal status, especially with regards to Canadian Customs, means that guns, particularly full black full metal guns, are more expensive here then elsewhere, often to the tune of three times as much. But as has been mentioned, once you're Age-Verified for ASC our classifieds will have whatever your heart desires, any brand name, any model, new or used, as long as you're willing to pay. TM AKs are pretty common and you shouldn't have any trouble replacing your favored gun once you're AV'ed. Just be prepared to spend in the area of $500-700.