Colin's impetus in writing those posts was to comment upon the widely-held perception of Batman's early days within comics fandom and the reality he found within the trade paperback. As Colin notes, fandom has come to believe the early days of Batman were more violent and dark, representing the ideal version of Batman, the one who Frank Miller and others firmly reestablished. In those circles of fandom, the accepted wisdom was that the arrival of Robin in Detective Comics #38 lightened Batman up, clearing away the darkness of those early tales. That belief is hogwash, but comforting hogwash to those nostalgic fans.
In those early tales we can see much of what we know about Batman hadn't been figured out. The Batcave is nowhere to be seen, there is no Alfred and Wayne Manor is out-of-focus. Batman had no origin when he first appeared, with the iconic tale not appearing until his seventh adventure (Detective Comics #33). He wore short gloves in his first appearance, then went gloveless in the second (so much for protecting his identity!). In Detective Comics #28 we see his cableline (a silk rope) has to be thrown as a lariat; he won't begin using batarangs until issue #31 and doesn't attach his line to a batarang until #32. His first aircraft (the Batgyro) appears in #31. The shape and size of the ears on his mask are in constant flux in his early appearances but are mostly standardized by #33. It's also well-known that in those days his origin didn't include swearing a code against guns; the early Batman wielded firearms and he took the lives of several of his foes.
Yet even then, some elements of Batman were figured out sooner than you'd suppose - the yellow utility belt is right there at the outset. The arrival of Robin doesn't change much either - Detective Comics #38 was followed by Batman #1, featuring the first two Joker stories. The Joker is a cold-blooded killer who uses his rictus-inducing venom from the begining and Robin is present for it all; that issue also includes Batman's fight with the Monster Men, a story which notably demonstrates Batman was still using firearms after Robin and still killing opponents (as when he strangles a Monster Man to death).
Yet there's other notable moments in those tales. Colin noted in his posts how Batman was quite far from Grant Morrison's "can beat anyone with enough prep time" ubermensch; in these tales, Batman is almost never prepared, instead flinging himself into situations where he's repeatedly beaten over the head. As Colin notes, Batman seems to be more of an adrenaline junkie than a cerebral detective/scientist.
There are two different stories in this volume in which Batman is shot (Detective Comics #29 & 33); weirdly, both times he's shot in the right breast. The first time it happens because he stops to interrogate two henchmen while a third surprises him; even though Batman's gun is in his hand, the third henchman still gets the drop on him (since this is pre-Alfred, Bruce has to visit his family doctor to have his wound stitched up). The second time, he's about to destroy the villain's dirigible by hacking it up with an axe (one supposes he'd be a few hours on that job) when the villain enters the room from behind him and shoots him in the back. Poor butterfly. He reveals he was wearing a bulletproof vest, yet leaves a large puddle of blood and has to be patched up again.
Was Batman a terrifying creature of the night pre-Robin? Not especially. We contemporary readers have been indoctrinated with the idea that Bruce dresses up as a bat because criminals find it frightening. Not so much in the 1930s - in fact, in Detective Comics #34 when he sneaks into an underground lair he's greeted by an unafraid henchman declaring "A drunk! Probably from a bal masque. Get his wallet." This is the ideal Batman? The one who is targeted for mugging by petty criminals?
Batman's also a little lacking in terms of courage, I'm sorry to say. In issue #31 we suddenly learn Bruce Wayne has a fiancee - Julie Madison. Julie is hypnotized by the Monk, a werewolf who wants to make Julie a member of his pack. Julie is on a boat to Hungary, but Batman tails after her in his batgyro to ensure she's safe. Soon after Batman lands on the boat to comfort Julie, the Monk appears and uses his hypnosis on Batman. Barely able to respond, Batman manages to throw a batarang at the Monk, then climbs back up to the batgyro and resumes following the boat from the air. In other words, he left Julie alone on the boat with the Monk so he could spirit her away to his lair. Smooth move, detective.
Perhaps the best example of Batman at his thickest is Detective Comics #37, one which Colin rightly roasted. This story opens with Batman stopping his batmobile outside a house to ask for directions. Yes, you heard right, Batman got lost. As he walks up to the house he hears a scream. Bursting in he sees three men torturing a fourth man who is bound to a chair. Batman attacks the armed gunmen, defeating them, but when he unties the fourth man the fourth man hits Batman over the head then murders the first three men, leaving Batman there so he'll be accused of killing them. The killer mentions a Mr. Turg which, on a hunch, leads Bruce Wayne to scout a grocery store owned by a Mr. Turg. Sure enough, the store is a criminal front being used by the killer. So Bruce exits the shop, changes into his Batman costume, reenters the shop and punches the shopkeeper in the face: "I'm not buying anything this time!"
Great plan, detective: let the criminal know you're the same person who was just inside the shop purchasing items from him. Apparently the concept of a secret identity was a little theoretical at this point in time.
Perhaps a very important part of the legend of Batman was never to be found in the pages of the comics - it was inside our untrustworthy collective memory.