Can I get the Publishing Queue Log to show all publishing transactions, including instances where the transactions failed multiple times & then succeeded? It seems like the Queue only shows one failure, not all of them. Is this the case? I'd like a complete list of all failures, not just one.
The publishing queue will indeed only show the last transaction with a given state. If you have 10 failed publishing transactions, the queue will only show the last one, as we assume that the previous 9 are irrelevant to you.
As of 2013 SP1 Tridion actually keeps all the data - this was not the case before, in the database we would actually delete "irrelevant" transactions. Using TOM.NET or the CoreService you can get all the transaction history, but in the UI we still hide older transactions.
UPDATE This assumption I made here is incorrect, 2013 SP1 kept publishing history for deleted items (for bundle support) but not the history of all publishing for any given item/target combination.