Bhob,
I am also an accountant, note: taxation is not where my skill set is... Also anything I state is purely my opinion and not tax advice.
I think people over complicate the entire tax situation and implications of both LC and Folio... Look at who we are lending to and not what the direct cause of loss or profit is tied to contractually within the aggregate. We are -not- really investing through a broker in individual stocks. Who owns the notes that are tied to the performance of any unit of money that is "invested" through lending club.
As taxation is not my specialty I would be interested in hearing your thoughts, because you do generally go with the "closest" regulations you can apply and I think it's a pretty simple connection as to what to do with taxes here. The reality is we won't know who is right or wrong until it is really put to the test but until then, I KISS....