I second the MKS quick release pedals.

And if you want a small fold, flat bars are tough to beat. I put a set of Ergon grips on my Birdy and it helps a lot on longer rides.

http://www.ergon-bike.com/gb/en/product/gr2

That said, I don't think I'd be happy riding the Birdy more than 40 miles or so at a stretch. There's definitely something lost in riding a small wheel bike, at least in my experience. (Moultons or some of the more touring oriented Bike Friday's may be a different story, but they don't fold like a Birdy or Brompton.)