I kind of get where you're coming from coming from on that point, but I'm not sure that I can completely agree with that. Whether you're in Canada or the USA, you're protected by law from any form of discrimination. Granted, businesses have the right to refuse service to any given customer at their discretion, but when it comes down to refusing service to someone simply because they're gay, black, asian, etc is just not something that I can support. Now that being said, if a business owner, minister, etc refuses service to someone because they're a downright asshole and they're really hard to deal with, then I say by all means, deny service. In my opinion it shouldn't be based on any physical attribute that the person may or may not have, but rather should be based individually on how the person you are offering said product or service to handles the situation, rather than race, colour, sexual orientation, or any other physical attribute they may or may not have.
Don't get me wrong, because anti-discrimination laws DO exist, they should cover any type of discrimination, including discrimination against someone based on sexuality. But they simply should not exist at all, and one day they won't. However, until that times comes LGBT individuals should receive the same protection from discrimination as one would receive for race or religion.