Re: Hina and Smoker makes a nice couple.
That's not cool, all great shows needs at least some romance.
I don't know about that. DragonballZ never particularly focused on romance. Sure, some people got married and some had kids, but there was rarely any real building of a connection between the men and women in a romantic light.
It was more like, one second you see someone shows a slight interest in another, next second we skip ahead five years and there is a baby on the scene.
Closest thing to "romance" in DBZ was GohanxVidel, and even that wasn't that great.
Anyway, point is I imagine One Piece is following a similar route. Sure, the characters are predominately adults and a lot of it's readers are growing in average age, but it is still a Shonen at the end of the day. Shonen's are targetted at teenage males, some of which may have found some interest in ecchi, but unlikely to have found interest in romance.
Still, doesn't rule it out. And you are right, there are a lot of "great stories" that do involve some sort of "great romance". But not all great stories have to.
Besides, unlike other Shonen's One Piece isn't stuck in a school. The better Shonen romances I can think of usually have a more centralised location, whereas One Piece has a "moving" central location (the SH ship). Most character relationships between members of the ship and those outside are strong, but ultimately very brief.
More on topic though: I enjoy the Hina x Smoker relationship, though don't think it's necessarily shown any romance. More like two friends possibly looking out for one another. Always felt Smoker and Tashigi had a better chemistry, but that's also debatable since it could just be that we've seen them together more.