And what a great match she'd have been for Malcolm (yup, I'm a Reed/Sato 'shipper!)
No, I really disagree. I think Malcolm and Hoshi are too similar to have found any romance together. Plus the fact that he had several opportunities to respond to her, (like when he misunderstands her interest in his favourite food, when he sees her topless, etc.). He doesn't respond because he doesn't fancy her. He also speaks to her in a tone of voice that suggests he finds her a little annoying. If there's anyone he fancies, it's T'Pol; he makes that clear in 'Shuttlepod One'.
There's an obvious problem with only having two main female characters! They definitely should have written others in. We want to see romance but only believable romance. I can imagine Hoshi having a secret passion for the Captain that she can never really act on.
Hoshi's cute but very neurotic. I think she makes an interesting, though predictable character; there have been times when I've been tired of her whining and negative attitude.