My guess...
Cullen is a major NPC, like Scribe Girl and Leliana, but none of them are companions. Leliana is romanceable only if you have never romanced her in DAO. Scribe Girl and Cullen are romanceable. Cole is an NPC and not a companion. IB is a companion. So is the Grey Mustache guy and he is a rogue. I'm holding out hope for one more female companion.
Grey Moustache Guy? I think you're mixing two characters.
Dramatic Hands Moustache Guy and Beardy Chevalier-Warden are two different guys. Dramatic Hands appears to be Tevinter due to the design of his outfit. if he is not a mage, he is a pikeman, not a rogue, and that would put him in the NPC category. The problem with that is that he has been painted into the party in a few concept arts, so it's more likely that he is a mage (and may be the healer, in fact, as Solas and Vivienne both seem to be dps).
Cole will not be a minor NPC, if he is in the game at all. He will either be major plot character, or he will be a companion. I cannot foresee him being a major helper NPC, unless he's the master of the spy network. And that just wouldn't pan out with Leliana taking that role, unless it's Cole we're sending out and Leliana who's sending him. Given Gaider's feelings about Cole, I'd lean toward thinking he's either a companion or not in the game at all, which would leave the final rogue spot open for someone else.
Part of me wishes for more women, not for the guys to have "eye candy," because I think the women already in the game are lovely and awesome and distinct already and no one can tell me that they don't look quite memorable--but because, I repeat, underrepresentation is bad. Maybe they will make up for it with a surplus of female major NPCs at our keep/base.