Mmmmm
ITCZ, in your example, why wouldn't you declare an emergency????
As for the alt v gs issue
"glide path/altimeter realationship"
Is it not a check for both, and simply if it is not within tolerances, then you must discontinue the approach, and one would think you would find out why???
"The final aproach contains a fix (FAP) at which the glide path/altimeter realationship should be verified. If the check indicates an unexplained discrepancy, the ILS approach should be discontinued."