As for possible race gates;
-Cullen has said pretty rude things about both dwarves and Qunari in the past.
-Sera doesn't like nobles, the human Inquisitor is a noble.
-Varric has said he's not into humans and he has issues with Qunari.
-Dorian is from Tevinter, which has issues with Qunari. (His opinion has never been stated and may easily not align with Tevinter's.)
-Vivienne may be gated because of her image issues and the scandal dating certain races could cause.
-Solas doesn't connect with dwarves because of their fade connection theory. (Fan theory without any real hints from official sources how he feels about dwarves.)
None of the above would surprise me. My guess is that Vivienne will be bi and available for humans and maybe one other race and Cullen or Dorian will be the gated male, with Solas as an ungated bi male. I'm leaning towards Cullen as gated, since he's shown dislike for certain races before. I don't really think Solas will actually have a problem with dwarves. Second possibility is that they planned all the gated options as males (Iron Bull, Cullen, Varric) and it would likely be Solas as a bi, ungated option and Varric just for female dwarves. I'm leaning towards Vivienne/Solas as bi options, though. It's just such a great opportunity to give everyone equal options, I hope they took it.