-below 200 ft, the mode become a combined mode like LAND. FLARE...(replace the 2 mode for alt and track)
the only way to go around is to move the throttle to his G/A position.
if you see no flare before 50 ft, you have to flare manauly, or you will land very hard.better to keep a hand on the stick and be ready....
-in combined mode you can not change your altitude by pushing/pulling the alt knob on the FCU(open or managed climb)
-I presume if you lose your ILS signal above 200 ft, you will have a warning, the plane will revert back to a normal rate of descent of 5%, or 3 degrees.
try this in the sim...