While you wait for fresh answers from qualified experts, you may be interested in a past thread on the topic.

What is the truth regarding Benedict Arnold? Why exactly has is name become common with traitor? with a detailed response by /u/zuzahin.

Interestingly, this is the only detailed response I could find about Benedict Arnold. I thought for sure there would be a ton of threads about him here, but there are really only a couple dozen threads specific to Arnold, and very few detailed responses.

There's always more to be said, but you may find more information about America's most infamous turncoat in a recent post by u/enygma9753.

Much attention is given in America to Arnold's prickly relationship with George Washington, the Continental Army and Congress, his military feats leading up to the Battle of Saratoga and the injury that would sideline his career and later prompt him to seek recompense and advancement on the British side.

Little is mentioned about his colourful post-Revolution life in British service -- in Canada, the Caribbean(!) and exile in London -- which you can read more about in the link above. He had a knack for alienating both sides in the Revolution due to his personality, litigious nature and his habitual need to right any perceived slight to his reputation.

Arnold is often demonized as a traitor, but at the same time some of his grievances about his alleged mistreatment by the army and Congress had some truth to it. In the disastrous 1775 invasion of Quebec, Arnold spent out of pocket to help finance the project and believed he should be compensated and/or promoted for the effort (esp. since he was injured for the cause during the attack).

Had he not made the fateful decision to assist John Andre and betray the Revolution, he would likely be considered a hero of the Revolution based on his record. In a twist of fate, the British didn't view him as a hero either and he never really received the praise and honours he had expected from them.