Have you ever brewed with buckwheat honey? I have. I will not do so again. All of the sweetness ferments out and you're left with the strong flavors of the buckwheat. I did not like it, but was able to give it all away to someone who did. I found the flavor to be overpowering and IIRC somewhat medicinal. Not at all pleasing to my tastes and it may clash with the fruit flavors you're looking for. I'd go with clover, orange blossom or wildflower honey, myself.
I also would recommend against the roasted barley for this style.
I say keep it a quad, not a dubbel, and check out Denny's 400th. I brewed that recipe for my 40th (birthday, not batch) and was quite pleased. Served it on tap and only got to age a small handful of bottles. It's on the "brew again" list.