Is Lon'qu gay?

No. His most noteworthy trait is that he is uneasy around girls due to of a traumatic experience he had when his "girlfriend died because of him." I am fond of the supports he has with Nowi when they are playing house. He doesn't seem to mind her since she looks like a child not a fully grown woman.

Finally, someone who isn’t afraid to ask the tough questions

You might want to double check your friends name...

No, but if you pick a random archer there's like a 30% chance they are.

It's probably just that your friend set that as the name to form a message with the greeting text. Putting nouns in place of the names makes for some funny messages.

Example: You know my ass, yes?