I like that the cargo bays are offset. And the aft bridge is something a buddy and I were recently discussing - it just makes more sense that it would be there so the crew and cap'n could keep and eye on things.
The blue kinda works if it were like a company color/trademark. I think something like yellow would imply caution in movement though.
Nonsense, she may 'lack detailing' as you put it but that is fine. Personally when I design a ship I fall back on over-engineering them so they look like chunks of machinery with exposed machine guts all over them but there is a place for a smooth vessel such as this, and smooth meaning plating which is less likely to be compromised by space debris or weapons fire. I see nothing wrong with this design that (if you were so inclined) would not be fixed by adding additional detailing, Obey-Art.
I'm guessing the blocks are detachable, aren't they? In that case, I could envision multiple types of cargo, and the ship could carry vastly different masses and lengths of crates. You could probably make detachable modules allowing the ship to serve other purposes; miniature carrier, support vessel, tug-boat...