If you are crossing frequently enough there will be questions by CBSA. And if you get caught they'll boot you out. They aren't just a friendly wave you through anymore. As a Canadian I can tell you there are rules and regulations. Canada, like every other country, isn't open door come on in. You have to prove you can support yourself (via a sponsor like a family member or a job), a needed skill, or have a hefty sum of cash to invest. If you can manage either, put in a PR application. It's faster from outside Canada though for it to be processed.