It is dangerous in the way that one does not get a confirmation of LED/slats movement. Suppose one get no LEDs and continues slowing down to 170 kts, in the turn to final if one is heavy and sloppy with speed control, one might get the shaker. Also, if an assymetry were to occur betwwen F0 & F1, one may not be able to stop the problem and could continue in assymetry and increase the roll tendencies. The first flap gate in any airplane is very important for movement confirmation and one should stop to check. Those that feel rushed on the app with all the flap selections, should select them and get stabilized sooner until they feel more comfortable with the airplane. The profiles are the result of many flight hours test and provide the safest most efficient approach, therefore they should be followed I believe.
As for F2 position, those operators that ignore it may be for cost savings on rwy analysis as it probably gave them little advantage for the fields they use, otherwise they have voluntarily deprived themselves of a very versatile TO flap setting and tons of extra pay load. As I said, 6500'-7500' rwys are best served by flaps 2. Hope this helps.