Are there ILS approaches where descending by the glide slope outside final might be dangerous?
Are there ILS approaches out there where descending by the glide slope on a segment of the approach that's outside the final approach segment would cause the aircraft to descend below the no lower than altitude for the segment?


Yes.  See InFO 11009.

In part the InFO reads:


  On ILS approaches, stepdown fixes are established for obstacle or traffic separation.  For all practical purposes, the glide slope remains stationary regardless of atmospheric temperature and pressure.  Conversely, stepdown fixes are published for a pilot to fly using indicated altitude, which varies with temperature and pressure changes.  Therefore, the proximity of stepdown fixes in reference to the glide slope, changes with the weather.


We know the old adage:


  From high (hot) to low (cold) look out below.


What isn't obvious about that adage is the perspective of that statement.  It is from the perspective of the pilot to the ground.  A glide slope's perspective, if you will, is from the ground to the pilot.  Thus what you will experience is this.  In warm weather, the stepdown altitudes will be higher than the glideslope and you will need to level off to remain above the MEA until crossing the next stepdown fix.

You must remain above the MEA at all times till crossing the precision final approach fix.