Radical idea -- as you promised it would be.
I am sorry to disagree with you, but that would not work emotionally for me. There are a number of reasons, but one might start with the premise you suggest that Han/Leia's romance worked fine "without needless dialogue."
quote: "The fact is, Han and Leia never talked that much. They didn't need to. It was all in the subtext. "I love you." "I know." And so did we without a bunch of needless dialogue."
That's simply not true -- Han and Leia have tons of dialogue in ESB and all of it, every single "I'd sooner kiss a wookie!" is building the romance. They even have all that terrific ANH dialogue to build upon. Their romance works in part because they are such unlikely lovers -- they seem so at odds and argue so much. But when a little tenderness creeps in, we feel how natural their love could be; how complementary they could be.
The problem in Episode II at the concept level isn't really that big -- the romance of Anakin and Padme is dramatic and full of trouble because of their different backgrounds and vows of chastity. They are forbidden to love and know it will cause only trouble. They swear to supress their feelings. Yet circumstance and desire pulls them together against their better judgment and they choose to marry in secret.
That's not bad. Not great, but not bad. It could use another wrinkle -- a personality conflict of greater weight and a better drama to pull them together -- but the skeleton there is okay.
The problem is that these elements are told so f**king poorly!
I think your suggestion would be interesting to see, but I can tell I would like it less. It's not taking best advantage of the footage we have if they were already secretly lovers instead of just now becoming lovers -- not in my opinion.
Making them lovers already gives them less, not more drama. If they're already lovers, what happens in this story to threaten that? Not much aside from a momentary attack of reason when Padme says this just can't be, she won't give in. If they're already lovers, that beat won't even make sense.
I am optimistic the changes Trooperman plans will make this the romance of a worthy and humble Jedi apprentice who loves a queen from afar, gets paired with her as a guard, and wins her love. Trimming the dialogue/massaging the action and letting us into Anakin's head via his dreams of Shmi are all going to make this the story it was always trying to be.