That's why I love Kaidan, he's laid back and sincere but he also has his own thing going on and is an accomplished soldier and biotic. He's not flashy, doesn't need to have sex with everything that isn't nailed down, and doesn't have a million witty one liners tucked away. After a while that can get boring. But as much as I enjoyed my romance with Kaidan, I wouldn't mind a clever dark type or a rough soldier (without the brofist bs_. Perhaps a renegade nerd like Mordin in ME2. 
Wow. I am surprised that there are people who actually get Kaidan Alenko and like him for it. I've always liked him.
As for romances, I wish Bioware would go the route of Mass Effect 1 romances. In ME1, there are no special quests or what have you, it just naturally develops. The love interests can even initiate flirting with Shepard or express some form of interest. In ME1, the romances were just icing on the cake.
DAI, for example, made the romances too unnecessarily over the top and turned it into a "you do a quest or two for me, get me stuff and I will bang you" type of affair. Plus the potential love interest do not express interest in the Inquisitor either, its as if they had no romantic inclinations until the Inquisitor flirted with them. It felt very artificial.
Stick with keeping it simple.