1) what the legal and ethical framework is surrounding the disclosure of highly confidential information by the president (and the consequences of breaking those limits);

McMaster spoke to this a little bit in his press briefing today:

The premise of that article was false; that in any way the president had a conversation that was inappropriate or that resulted in any kind of lapse of national security ... What the president discussed with the foreign minister was wholly appropriate to that conversation, and is consistent with the routine sharing of information between the president and any leaders with whom he's engaged

The framework he seems to allude to is one based on "lapse of national security", and he asserts that the conversation did not run afoul of that. Or, as WaPo less charitably puts it, McMaster's ethical framework for the disclosure is "anything that comes from the president is okay".