As much as I'm all for being inclusive of all different types of relationships - I think you do have to remind yourself that Dragon Age is primarily an adventure/story-based RPG. Yes, the love story definitely adds to that experience, and I love that Bioware includes LGBT options (or hell, options for straight females, for that matter), there's a point where i feel like the things people are asking for here go into 'perhaps you should play a dating sim...' territory. I really don't want to be rude, but while reading some of these posts about these complex variations on relationship types I had this image pop into my head....
*Our hero goes into a room, alone. Locks the door. Looks around surreptitiously before reaching for his armor. Scene fades to black...*
Oh, don't mind me... My point was, where does it end? I mean, as cool as it would be to see a realistic, healthy portrayal of, say, a D/s relationship, I would never expect Dragon age to actually go there. A simple love story that adds to my interaction with an interesting character is quite satisfactory, thanks 
Personally, I'd just like more of those little touches that make the relationship seem more real - something more than just a couple cheesy flirt lines and a makeout scene. i.e., the Garrus romance with it's little 'date above the Presidium' scene or where your LI comforts you after your mother's death in DA2.
Also, better flirt lines. Partly it was due to the voice actress I think, but pretty much everything that came out of FemHawke's mouth when I clicked that heart icon made me cringe a bit.