I agree on all counts except the third. The French built the Maginot Line specifically to force the Germans to go through Belgium, which was where they intended to fight the German army (thereby ensuring that French soil wouldn't be devastated like it was in WW1) under their strategy, the Dyle Plan (so named after the Dyle River in Belgium). What went wrong was that the Germans punched through the Ardennes forest, which the Allies had mistakenly concluded would be impassable for their panzers and thus left in the hands of their weakest formations to defend. The best units of the French Army were thus left trapped in the Low Countries with only scattered second-rate forces (and no real strategic reserve, since said reserve was committed to fight in Belgium already) left in the way of the German vanguard in France itself, hence, their total defeat shortly afterward.

The French strategy & generals were retarded, but not as retarded as they were in WW1, and to their credit the Dyle Plan was a little more sensible than its equivalent at the start of the latter conflict, Plan XVII.