@dream_operator: While it might be nice for a shy character to have Zev be more forward, it would be an odd choice for the devs to have him do so, and I'm not just referring to the possible backlash from straight guys that are already annoyed that he flirts with them at all. Zev has pretty much willingly made himself your slave, and it is entirely possible to RP a Warden who treats him as such. The Warden doesn't have the option to tell him he is free to leave if he wishes until his approval is pretty high (which is when the more than a friend line can occur). Even after that, Zev is very much at the Warden's mercy until after Taliesen (and after depending on the dialogue choices).
Morrigan's line when her approval maxes out makes sense for her character, and it really isn't any more forward than Zev's. If you tell him that you think of him as a friend, he will ask if it could be more, and Morrigan does basically the same thing, though she does initiate the conversation. She has to get one of the Warden's in bed and she is certainly not dependent on the Warden otherwise. It makes sense for her character to be more forward. The line itself isn't all that different from Zev's, she just initiates the conversation.
Al is so utterly inexperienced, it makes sense for him to not make the first move. His character is very passive. There are subtle lines (like the one about the future) that can turn on his romance, and after that he makes it clear that he is interested. He is also conflicted from the beginning about starting a romance because he knows full well he may well be put on the throne.
Lel's romance starter lines are not all completely obvious (shoes?!), but unless the Warden accidentally starts the romance with one of those, she is only forward if her very buggy romance flags accidentally fire. Not all of her starter lines are overtly flirtatious either, and of all the romances, the conversations leading up to the tent are by far the least sexual and flirtatious (which is how my first character accidentally romanced her).
It is possible to romance any of them with a shy Warden. It's just more of a challenge.
And with that wall of text, I am going to get more coffee.
(Added because I am really loving this character, and I finally found a second armor that I like on an elf)