Under (a) You must follow the track down to the MDA level, and then climb as directed. It may be a level segment, it may be a direct climb, but you still drive down to that point.
Where the heck are you reading that?
It is plainly stated that you are OUTSIDE the nav tolerance, and are NOT permitted to continue the approach, and definitely not descend to MDA (because you are no longer in the protected area), so pour on the coals and climb out of there, and follow the tracking directions on the plate.
In case (b) the assumption in the regulation is that you were on the flightpath, and after the MAP/MSA, the radio aid fails.
Again, where are you seeing that? The aircraft is probably below the 10nm MSA, but not yet reached the MDA or MAP, and the aid fails or becomes suspect. Again, you cannot be sure where you are, and the only place you want to be is NOT where you are. Make Mister Proach.