I regret to say that I won't be able to address this in the Mr. History column. After much research I've discovered some very interesting stuff, and although I could answer your question, I can't really add anything to what Cornwall said in the end notes to "The Fort," or to what's in the great book, "The Court Martial of Paul Revere," by Michael M. Greenburg, which came out last October. Since I can't find anything new to say its not the best article topic and I'd be treading some well-travelled ground. But I learned enough to discuss your question in this forum.
You wrote that Cornwall portrayed Revere as "inefficient, self serving, insubordinate, and perhaps outright cowardly in his actions." I think that Revere was 1. inefficient, 2. self serving, and 3. insubordinate. He was not, in my opinion, cowardly. Revere strongly desired a Continental commission and if not that, military glory, at least. Trouble was, he probably was not cut out to be a senior military commander. He was certainly brave and dedicated to the Patriot cause, but he had no background, experience, or training that helped him learn how to command military units. His command of the Mass. Artillery at Castle Island in Boston Harbor was checkered. The Penobscot expedition was poorly led, planned, and executed from the top. That's an environment that often does not bring out the best in weak leaders. In action his artillery was marginal at best, inept to a harsher critic. The Penobscot expedition overwhelmed Revere as a leader and artillery commander. It was just a mess that he did not rise above.
However, I don't think he was cowardly. A train wreck of an operation like the Penobscot expedition often makes novice leaders fall back on their comfort levels. Revere's comfort level was probably as an individual, not a unit commander. I don't think he was trying to avoid danger, but I get the impression he concentrated on his own comfort above that of his soldiers. That's the mark of someone who has never been trained on leadership, as Revere never was.
Its interesting to note that in the initial inquiry into the disaster, Revere strongly defended himself and took apart much of the testimony of witnesses against him in methodical cross-examination. The first court martial ruling placed blame for the expedition's failure on Commodore Saltonstall and did not even mention Revere. It was Revere, still feeling a cloud over his head from the original accusations, who kept the controversy alive by continually asking for another court to clear his name. He had to request it no less than 9 times between 1779 and 1782 before the state of Massachusetts granted his request. Their final decision was that Revere was only guilty of not immediately obeying Gen. Wadsworth and providing the general the use of his boat on the day of the withdrawal. I found one thorough research paper where the author agreed with the court's rulings, in that Revere's conduct was probably not very honorable, but short of incompetence. The author also determined that based on the available evidence, a modern court martial probably would not convict Revere of cowardice or incompetence under the Uniform Code of Military Justice.
You also asked "how much can be blamed on Massachusetts trying to "take all of the glory by using only minimal Continental resources?" I don't think much of the blame should go to the state. Defending their state from a minor British incursion, which is what the British fort was, was something that was within the intent and capability of the Massachusetts militia. In the summer of 1779, Washington was defending West Point from Clinton's push up the Hudson and he had 1,000 troops in the Mohawk Valley suppressing the Indians, and he was loathe to detach troops to address distractions. As an example, in early July the British launched a series of very destructive raids on the Connecticut coast and Washington only grudgingly detached one brigade to help after repeated pleas from Gov. Trumbull., and even that brigade he kept on a short leash to return immediately. The British fort at Penobscot was not necessarily a Continental problem, and I don't think the Continental Army had any troops to spare for Penobscot. And the Massachusetts expedition would have succeeded if the commander, Gen. Lovell, had pressed his assault. The issue only became more than the militia could handle when Lovell failed as a commander. Only one caveat - in research, I came across one secondary reference stating that the Massachusetts government actually discussed calling for Continental troops but passed so as not to share the expected laurels. Alas, I was not able to track that statement down to its primary source to confirm it. If that statement is true, it sure gives credence to your point.
Lastly, I could not confirm that the costs of the failed expedition bankrupted Massachusetts. I know that the disaster was huge, that it wrecked the state's naval resources, and that Congress awarded Mass. $1,248,000 in 1793 as compensation for the state's losses (though I'm not sure if that was for losses during the entire war of just for the Penobscot expedition).
In the end it looks like the longest lasting damage was to Revere's reputation. I don't think we can judge Revere too harshly though. He proved his bravery and dedication to the American cause in the early days of rebellion. He was not a great leader in the Penobscot expedition, but that was because he was never taught the be a military commander and the expedition was a mess from start to finish. When it comes to blame for the expedition, there was plenty to go around. And the fault for the failure of the expedition, to me, goes to Gen. Lovell. The whole expedition was a sad moment in the Revolution but Revere should not be the lightening rod for failure. Though he called himself "Col. Revere" to his death.
If you want to read more, check out "The Court Martial of Paul Revere: A Son of Liberty & America's Forgotten Military Disaster," by Michael M. Greenburg. I also have several links to some on line resources that I'll be happy to post if you're interested.
I hope that answers some of your question, thank you for your patience, and please accept my regrets for not being able to do a full article on this fascinating question.
Author of George Washington and the Final British Campaign for the Hudson River, 1779
The 83rd Pennsylvania Volunteers in the Civil War