BoA was never at risk of failing. They stepped in to buy Merrill Lynch because basically the treasury ordered them to, but they didn't need TARP to absorb the continued losses in that unit, and paid it back with interest as soon as they were allowed to.
They weren't at risk of failing when TARP passed. If TARP hadn't passed, and a few of their counterparties had gone bankrupt, they might have been next as the whole system went under.
Yes and that is why they did what the Treasury told them to. It was directly in their shareholder's interests to support the recovery of the banking industry. Ken Lewis still lost his job for doing it.
Yes, they were, that's why the systemic risk exception was invoked for them.
> but they didn't need TARP
They needed the systemic risk exception and their own specific, $20 billion capital injection and government loss protection bailout plan very similar to Citigroup's to be announced (the announcement itself stabilized things enough that they ended up not needing the bailout, which also happened with Wachovia’s before Citigroup.)