Bilbo is a much more interesting character than I had remembered. His moments of heroism are not through violence but through moral strength: in particular, his attempts to prevent the Elves and Dwarves from fighting. That said, the Gollum business and the Arkenstone incident both show certain ambiguities in his heroism.
Gandalf, somewhat to my surprise, comes over as an arch-manipulator. He pulls Bilbo onto the adventure very much against his will, and the battle with Smaug and then the Goblins is almost a proxy conflict for the ongoing Cold War against Sauron/the Necromancer, the point being to consolidate the northeastern corner of the map. But it looks rather like the Battle of the Five Armies is a deliberate rehearsal for the War of the Ring, orchestrated by Gandalf.
I've been reading the edition with Tolkien's own sketches. Let's be honest: they are not very good - studies of perspective, really, with the humanoid figures barely recognisable as such. The trolls in the picture hide behind the trees, in clear contradiction to the text. Providing the author's own drawings gives some extra authenticity, but I think they could have been saved for one of the spinoff volumes.