i would prefer bg2 style romances, along with friendship path.
that would mean- 30+ talks that give TIME for any relationship to have actual depth. no mostly plot-related talks, or only-in-camp comments. i loved how npc's slowly developed over time, throuh many talks and additional mini plots. of course, i assume a more mature handling of the matter, above 12yo mark (no sex being the point of it all, no constant psychotherapy for companions etc.). on the similar note, i would prefer if romance would not be important for any bigger event, only showing few minor consequences, like bg2.
people love flaming romance threads, but like it or not sex (desire) and love (emotional connection) are integral feelings for any average human being, and since this is RPG, such matters are not beneath inclusion in videogame, quite contrary.
i cannot imagine adventuring through hells and world shattering experience with a set of companions, without any need to at least find temporary comfort in situation where you don't know if next fight will leave you dead. emotions tend to run high at times like that and people tend to connect because of similar experience and interests. i'm not saying it's impossible not having sex or romantic relationship, but that's why you decline it.
it makes no sense to me to remove the option to have romanceable companion if people want it, because some don't care for it. if obsidian decides to include such content, i hope they show some balls- no excessive carefull approaching the player, highlighted romance options and similar bull****. in real world you also dont have the luxury to direct others emotions, you only react to them. so if NPC's start talking, perhaps showing their attentions clearly or perhaps just getting to know you better, before revealing their feelings. at that point you get to decide if you shut them up, remain friends or develop relatonship. just like you can make the same choice of fihting or not, siding with one faction or the other.
edit- i noticed it is being talked about bisexuality. i support bisexual and gay content fully. romance is good or bad because of writing not because of "unrealistic game flag that decide if NPC is gay or bisexual based on PC gender", as seen already in DA2. romances there were bad because of lazy and sleazy writing, and nothing else.