4) For my employer, the answer is "don't depart", and I don't have the AIP to hand to check the general case. But I would think the answer is something like Grid LSAlt. You cannot be in IMC below this altitude without a functional primary means navigation system.
6) Use the lowest DA unless, at the start of the approach, you know that you cannot achieve the required gradient to make good the published missed approach. In this case, choose a higher minimum. It would be good airmanship to consider the possibility of an engine failure at DA when not visual, but not a legal requirement.
Last edited by Oktas8; 27th Feb 2013 at 02:41.