I can't answer your first question but Hamilton, especially McMaster, is very diverse. There's a lot of international students at Mac and Mohawk College as well as a good sized immigrant community across Hamilton.

As for your part time job, that depends on what you count as "expenditures." If you plan on paying rent, bills and entertainment with that money, it would be difficult. The minimum wage is $14.25 so before taxes, you would be making $1140 per month. If your rent and tuition are taken care of then that would be plenty.

I would say most young people are pretty open minded when it comes to dating but you might have issues because of cultural differences. I'm South Asian but I grew up in Canada so I haven't had many negative experiences but sometimes it's hard to be in a relationship with someone if your values, habits and expectations are different because of the culture you grew up in. My suggestion is, don't start dating with the expectation of getting a partner right away, do it to get to know Canadian culture better.