I think your analysis is generally correct, except that the answer to a(ii) is "we don't know."
Could the CIA have sent Plame on overseas trips within the past 5 years using her cover as an "energy analyst" for "Brewster Jennings"?
Who knows?
Would it be incompetent to send on an overseas covert assignment an officer who has already been "outed" and who openly drives herself to work at CIA HQ everyday?
Yes, to me that would be incompetent.
But who here thinks, in the case of an agency dysfunctional enough to keep around an idiot like Larry Johnson as an intelligence analyst, that the CIA is not so incompetent as to do that very thing?
There are probably grounds to challenge the "affirmative steps" part. Were I representing Rove or Libby, I would take the position that "affirmative steps" has to mean steps by the CIA that, when taken together, are reasonable to assure that the agent in fact is covert. When an agent is already "outed" by Aldrich Ames and drives herself to CIA HQ everday, the mere fact that the she pretends to be an "energy analyst" for a front company is not a sufficient "affirmative step" to reasonably accomplish the purpose of making her a "covert agent."
A search of www.google.com demonstrates that.
She may have been pretending to be several other people as well, and probably knows Larry Johnson from the doctor's office!
Could she have been covert in open view?