What can the bosses on the down tube, next to the front wheel, be used for? The only thing I can think of is a mountain bike style mudguard, but I've only seen ones that clip on.
They are most likely bosses for a "Crud Catcher", a type of mudguard usually clipped to the downtube. Some frames allow them to be bolted to it rather than fastened on with rubber o-rings.
I would have to assume those are the...
Extra Features: Tyre clearance for up to 700 x 45c with full mudguard and rack mounts
...that are mentioned on their website. Too far apart and to close to the tire to be anything else really.
That's where I put my pump, so maybe they're for a pump. It looks like a road morph like I've got or an old fashioned pump would fit there. Most pump brackets will fit bottle cage screws or clamp on directly to the frame so it seems a bit unnecessary.
I was right next to one of these bikes on the train yesterday and there's quite a bit of clearance there.