Yeah, you can obviously be straight/bi/ace/gay in a social circle consisting primarily of a differing sexuality. But in this case it would mean that a gay Fereldan would be a societal outcast. That's why I suggest Orlais or Antiva as more likely alternatives. Having a gay Fereldan runs the risk of the character having his sexuality be PART of their character, because its why they're culturally divided. And that's a problem on its own. I think everyone here agrees sexuality is not personality, so it may be best to put them in a region where it is realistic to make it a non-event, so it can be mentioned freely (rather than kept secret as if it is shameful) without people around them freaking out or, at the least, treating it as big news that affects their personal view of them as a person.
It's possible to have them from Fereldan of course (I did say 'probably') but it would be a lot harder to do it without people complaining. There are literally always people complaining. About anything. Everything. This is the internet. Best to try and reduce the hate mail the creators get by reducing the margin for error.
Um, where are you getting your assumptions from? According to World of Thedas (page 72), Fereldan is only slightly more close minded than the rest of Thedas. Just like with most countries in that setting, Fereldan really doesn't care unless you're noble. Now granted, being overt in your affection is considered tasteless. That doesn't solely apply to LGBT couples either. They frown on anyone being too amorous while out and about. I took that to mean "No making out in public." Otherwise, even if you're a noble, so long as you produce an heir and keep up appearances, no one really considers it an issue at all in Fereldan. If you're a normal citizen, not a toss shall be given about who keeps your bed warm.
Also, a non-hetero Ferelden wouldn't have his sexuality define him or her anymore than, say, Dorian. Sure, it would probably come into play with their story, but no more or no less than any other character from any other nation.
Secondly, that last paragraph is just flat out wrong about how much BW cares about those that despise having LGBT relationships in their games. BioWare has already gotten tons of hate mail regarding any sort of LGBT relationships and characters. They don't care about the hate mail, and will gladly tell you as such. If they decide to include a gay/lesbian Ferelden character, they'll just do it. After over 6 years of hate mail for LGBT relationships, they truly aren't going to care about this.
You do realize that if Focus on the Family and other such groups didn't stop EA/BioWare from including same sex relationships, a handful of mouth breathers writing some angry letters isn't going to affect a thing.
Not to mention that BioWare doesn't care about keeping any sort of majority happy. They care about producing a good game for everyone. That's been their credo and it isn't going to change. Honestly, if they cared about making the majority happy, they would have gone back to having most of the LIs for straight men.
Finally, most of the folks that play this series don't give a crap where the LGBT LIs are from. The nation is secondary to the representation. The DA team isn't going to exclude the idea of a Ferelden gay/lesbian LI just because a few loud players might not like it. Given the history that both BioWare and EA has had with the LGBT community, to make such an assumption is silly and erroneous.